MARY BETH KELLY, J.

This case concerns whether the 2010 amendment of the Motor Vehicle Dealer Act (MVDA),1 expanding the relevant market area — the area within which automobile manufacturers are required to notify an existing dealership of the manufacturer's intent to establish a dealership selling the same line of vehicles as that existing dealership — from a six-mile radius to a nine-mile radius, applies retroactively. We conclude that it does not. The 2010 Amendment of the MVDA contains no language suggesting retroactivity, and applying the amendment retroactively would alter the parties' existing contract rights. A manufacturer-dealer relationship, absent contrary language in the contract, incorporates the relevant market area in effect at the time when the dealer agreement was entered. The six-mile relevant market area in effect in 2007, then, governs the 2007 manufacturer-dealer agreement at issue in this case. We therefore vacate the judgment of the Court of Appeals and remand this case to the Washtenaw Circuit Court for reinstatement of summary disposition in favor of defendants Chrysler Group (Chrysler) and IHS Automotive Group (IHS).

I. FACTS AND PROCEDURAL HISTORY

Chrysler and plaintiff LaFontaine Saline Inc. (LaFontaine), an authorized Chrysler automobile dealer, entered into a Dealer Agreement on September 24, 2007. The agreement granted LaFontaine the non-exclusive right to sell Dodge vehicles from its location in Saline, Michigan, and defined LaFontaine's Sales Locality as "the area designated in writing to [LaFontaine] by [Chrysler] from time to time as the territory of [LaFontaine's] responsibility for the sale of [Chrysler, Jeep, and Dodge] vehicles, vehicle parts and accessories...." The agreement further provided that LaFontaine's "Sales Locality may be shared with other [Chrysler] dealers of the same line-make as [Chrysler] determines to be appropriate."

The parties agree that the 2007 Dealer Agreement is subject to the MVDA, which regulates relationships among automobile manufacturers, distributors, and dealers. In particular, the MVDA's relevant market area provision limits Chrysler's right to establish dealerships of the same line of vehicles in the vicinity of LaFontaine's existing dealership. This section, MCL 445.1576(2), provides:

This notice requirement further entitles a recipient dealer to file a declaratory judgment action requiring the manufacturer to show good cause for establishing a new dealership within the relevant market area.3

At the time Chrysler and LaFontaine entered into their 2007 Dealer Agreement, MCL 445.1566(a) defined "relevant market area" as "the area within a radius of 6 miles of the intended site of the proposed or relocated dealer."4 Significantly, this same six-mile radius was in effect when, on February 2, 2010, Chrysler and IHS, another Dodge automobile dealer, entered into a "Letter of Intent to Add Vehicle Line" (LOI). The LOI provided that Chrysler "will accept [IHS's] offer to enter into an Agreement" to sell Dodge vehicles upon IHS's satisfaction of certain conditions enumerated in the LOI.5 The LOI further provided Chrysler the discretionary right to terminate the LOI should "anyone file a protest or lawsuit, demand arbitration or otherwise challenge ... the proposed establishment" if the challenge is not withdrawn or dismissed within 90 days of filing.

After execution of the LOI, the Legislature expanded the statutory definition of relevant market area from the six-mile radius to "the area within a radius of 9 miles" of the intended site of the proposed or relocated dealership.6 Although the proposed location for IHS's Dodge facility is outside the pre-amendment six-mile radius of LaFontaine's existing dealership, it is within the post-amendment nine-mile radius of that location. On September 3, 2010, LaFontaine contacted Chrysler, indicating its protest of the proposed IHS Dodge dealership location in light of the nine-mile radius established by the 2010 Amendment. Chrysler responded on October 8, 2010, communicating its continuing intent to establish a Dodge dealership at IHS's Ann Arbor location.

LaFontaine then filed a complaint for declaratory relief, challenging the proposed dealership under the MVDA. Chrysler and IHS responded with a motion for summary disposition, alleging that the 2010 Amendment did not apply to the proposed dealership because their LOI predated the Amendment, and LaFontaine therefore had no statutory right to challenge it. They further argued that applying the 2010 Amendment to the LOI and to the 2007 Chrysler-LaFontaine Dealer Agreement would be an impermissible retroactive application of the law. LaFontaine argued that its 2007 Dealer Agreement with Chrysler did not address or refer to LaFontaine's relevant market area, and therefore application of the 2010 Amendment could not interfere with that agreement. Even if the 2010 Amendment applied only prospectively, LaFontaine asserted that the LOI did not constitute a dealer agreement, but merely an agreement for certain improvements to IHS's facilities in anticipation of a dealer agreement. Any formal dealer agreement, LaFontaine argued, must follow the August 4, 2010 effective date of the amendment and be subject to the nine-mile relevant market area.

The Washtenaw Circuit Court granted Chrysler's and IHS's motions for summary disposition, concluding that the 2010 Amendment did not overcome the presumption that statutory amendments generally operate prospectively only. The Legislature provided a specific effective date of August 4, 2010, and omitted any reference to retroactivity. The circuit court further found that the LOI between Chrysler and IHS constituted a dealer agreement under the MVDA, and thereby established the parties' rights upon execution. The court denied LaFontaine's motion for reconsideration, adding that LaFontaine's claim was not ripe because it "rests on contingent future events that may not occur," i.e., a formal Dealer Agreement.

The Court of Appeals reversed the circuit court in a published opinion, concluding that the issue of retroactivity was immaterial because the LOI was not a dealer agreement because it did not establish the "legal rights [or] obligations of [Chrysler or IHS] with regard to the purchase and sale or resale of new motor vehicles and accessories for motor vehicles."7 The Court of Appeals held that any dealer agreement could necessarily occur only after the effective date of the 2010 Amendment, and application of that amendment could not have retroactive effect on any dealer agreement between Chrysler and IHS.8 Moreover, because the 2010 Amendment applied and the MVDA allows a dealer to bring a declaratory judgment action upon notice of a manufacturer's intent to establish a like-line dealership, the Court of Appeals held that LaFontaine had standing to sue to determine whether good cause existed for IHS's proposed dealership.9 The Court of Appeals denied Chrysler's and IHS's motions for reconsideration.

We granted Chrysler's and IHS's applications for leave to appeal, requesting that the parties address:

II. STANDARD OF REVIEW

Chrysler and IHS moved for summary disposition under MCR 2.116(C)(8) and (10). Summary disposition under MCR 2.116(C)(8) is appropriate where the complaint fails to state a claim on which relief may be granted.11 A motion for summary disposition under MCR 2.116(C)(10) challenges the factual sufficiency of the complaint, with the trial court considering the entire record in a light most favorable to the nonmoving party.12 We review de novo a trial court's ruling on a motion for summary disposition.13 We also review questions of statutory interpretation de novo,14 including questions regarding retroactivity of amendments.15

III. ANALYSIS AND APPLICATION

In establishing whether the 2010 Amendment applies on the facts of this case, we first examine the source, if any, of the parties' contractual rights that predates the 2010 Amendment. Only then can we determine whether retroactive application of the 2010 Amendment's expanded relevant market area would interfere with any such rights.

A. THE SOURCE OF CONTRACTUAL RIGHTS

The MVDA in effect at the time of both the 2007 Chrysler-LaFontaine Dealer Agreement and 2010 Chrysler-IHS LOI defined "Dealer agreement" as

This provision of the MVDA specifies three key elements to a Dealer Agreement: (1) a writing (2) establishing the legal rights and obligations of the parties (3) with regard to the purchase and sale or resale of new motor vehicles and accessories for motor vehicles.

Applying these elements to the 2007 Chrysler-LaFontaine Dealer Agreement compels the undisputed conclusion that that agreement constitutes a "dealer agreement" within the meaning of the MVDA. The agreement is in writing, purports to establish the parties' legal rights and obligations, and sets out specific "Products Covered" in a "Motor Vehicle Addendum." The agreement therefore complies with the requirements of then-effective MCL 445.1562(2), and establishes the parties' contractual rights.17 And because MCL 445.1566(1) provided for a six-mile relevant market area at the time Chrysler and LaFontaine entered into their Dealer Agreement, the six-mile radius will govern that agreement unless the 2010 Amendment expanding the relevant market area is retroactively applicable to existing dealer agreements. Indeed, it is well settled that

Before reaching the issue of retroactivity, however, we must also consider the 2010 LOI between Chrysler and IHS and whether that agreement similarly meets the MVDA's definition of "dealer agreement." Like the 2007 Chrysler-LaFontaine Dealer Agreement, the LOI between Chrysler and IHS is a writing executed by both parties. However, while the language of this latter agreement speaks in terms of "requirements" and "breaches," and purports to constitute Chrysler and IHS's "entire agreement concerning the establishment of the Facility," the LOI is not a "dealer agreement" within the meaning of the MVDA because it does not establish their rights and obligations with regard to the purchase and sale or resale of new motor vehicles and accessories for motor vehicles, as the MVDA requires. Rather, the LOI speaks almost entirely to requirements IHS must meet before Chrysler will "accept [IHS's] offer to enter into an Agreement in its then-customary form" and likewise contemplates conditions IHS must satisfy "[b]efore [Chrysler] enters into an Agreement with [IHS]...."19 At most, then, the LOI is akin to an agreement to agree to a Dealer Agreement. While it is "`well recognized that it is possible for parties to make an enforceable contract binding them to prepare and execute a subsequent agreement,'" an agreement to agree is not enforceable where "`the document or contract that the parties agree to make is to contain any material term that is not already agreed on....'"20 Accordingly, the LOI was not a Dealer Agreement pursuant to MCL 445.1562(2) as was in effect at the time Chrysler and IHS executed their LOI. Chrysler and IHS therefore had no contractual rights by way of the 2010 LOI with which retroactive application of the nine-mile relevant market area could interfere.

B. RETROACTIVITY

Because the 2007 Dealer Agreement between Chrysler and LaFontaine established rights between the parties, we consider whether retroactive application of the 2010 Amendment's nine-mile relevant market area would impermissibly deprive Chrysler of any such rights.

To begin, we note that the 2007 Dealer Agreement between Chrysler and LaFontaine contains no language purporting to grant LaFontaine rights against encroachment by like-line dealers. Rather, the agreement explicitly contemplates that LaFontaine's "Sales Locality may be shared with other [Chrysler] dealers of the same line-make as [Chrysler] determines to be appropriate." This language makes clear that, aside from any limits set out in the MVDA (i.e., the relevant market area provision), nothing in the 2007 Dealer Agreement prevents Chrysler from reaching like-line dealer agreements with other dealerships within LaFontaine's "Sales Locality."21 Accordingly, any right LaFontaine has against encroachment by like-line dealers is a creature of statute. We consequently must determine whether the creation of a statutory right against encroachment by the 2010 MVDA amendment, applied against Chrysler's preexisting 2007 Dealer Agreement with LaFontaine, would result in impermissible retroactive application.

Retroactive application of legislation "`presents problems of unfairness ... because it can deprive citizens of legitimate expectations and upset settled transactions.'"22 We have therefore required that the Legislature make its intentions clear when it seeks to pass a law with retroactive effect.23 In determining whether a law has retroactive effect, we keep four principles in mind. First, we consider whether there is specific language providing for retroactive application.24 Second, in some situations,25 a statute is not regarded as operating retroactively merely because it relates to an antecedent event.26 Third, in determining retroactivity, we must keep in mind that retroactive laws impair vested rights acquired under existing laws or create new obligations or duties with respect to transactions or considerations already past.27 Finally, a remedial or procedural act not affecting vested rights may be given retroactive effect where the injury or claim is antecedent to the enactment of the statute.28

MCL 445.1566(1)(a), as amended by 2010 PA 139, provides:

Nothing in the language of MCL 445.1566(1)(a) suggests the Legislature's intent that the law apply retroactively. The Legislature "`knows how to make clear its intention that a statute apply retroactively.'"29 In fact, it has done so with other provisions of the MVDA, which explicitly provide that they apply to pre-existing contracts.30 The Legislature has even used specific retroactivity language when amending the MVDA.31 The Legislature's silence regarding retroactivity in its amendment of the definition of "relevant market area" undermines any argument that MCL 445.1566 was intended to apply retroactively. That the Legislature provided for the law to take immediate effect upon its filing date — August 4, 2010 — only confirms its textual prospectivity.32

The remaining factors in our retroactivity analysis require that we examine the amendment's effect on existing contract rights. A statute's relation to a prior event alone will not render the statute retroactive. Rather, we consider whether the statute "takes away or impairs vested rights acquired under existing laws, or creates a new obligation and imposes a new duty, or attaches a new disability with respect to transactions or considerations already past."33 LaFontaine asserts that retroactivity is not at issue in this case merely because it invoked the anti-encroachment protection of the 2010 amendment after that amendment went into effect. However, this argument begs the retroactivity question, failing to recognize that retroactive application of the 2010 Amendment would "create a new liability in connection with a past transaction"34 — namely, Chrysler's 2007 Dealer Agreement with LaFontaine. Applying the 2010 Amendment's nine-mile relevant market area to the parties' 2007 agreement would impose on Chrysler the new obligation of meeting the rigorous "good cause" standard in an action for declaratory relief under MCL 445.1576(3). Chrysler did not bargain for or contemplate this obligation at the time of its 2007 Dealer Agreement with LaFontaine, when the MVDA imposed only a relevant market area of six miles. Rather, Chrysler had the settled expectation at the time of its 2007 agreement that it could establish a like-line dealership anywhere outside a six-mile radius of LaFontaine's place of business.

Because Chrysler explicitly reserved its right to establish such dealerships within LaFontaine's "Sales Locality" as refered to in the 2007 Dealer Agreement, Chrysler's right is contractual in nature, limited only by LaFontaine's statutory anti-encroachment rights in the MVDA's relevant market area provision.35 Accordingly, retroactive application of the 2010 Amendment would not merely "operate in furtherance of a remedy or mode of procedure," and therefore cannot be characterized as remedial or procedural.36 Rather, the expansion of the relevant market area creates substantive rights for dealers that had no prior existence in law or contract, and diminishes a manufacturer's existing rights under contracts executed before the 2010 Amendment. Application of the 2010 Amendment would give LaFontaine the substantive right to object where it previously could not — that is, the right to object to a proposed like-line dealership more than six, but less than nine miles away.37 Because retroactive application of the 2010 Amendment would interfere with Chrysler's contractual right to establish dealerships outside of a six-mile radius of LaFontaine, such retroactive application is impermissible on these facts.38 Accordingly, the relevant market area in effect when Chrysler reached its 2007 Dealer Agreement with LaFontaine governs that agreement.

Our conclusion is consistent with the recent interpretation of this exact amendment of the MVDA by the United States Court of Appeals for the Sixth Circuit. In Kia Motors,39 the Sixth Circuit upheld a manufacturer's right, after the effective date of the 2010 Amendment, to establish a new like-line dealership approximately seven miles from an existing dealership.40 In doing so, the Sixth Circuit relied on the Kia-Glassman Dealer Agreement, which, like the 2007 Chrysler-LaFontaine Dealer Agreement here, predated the 2010 Amendment.41

Applying Michigan retroactivity law, the Sixth Circuit concluded that the 2010 Amendment did not apply retroactively.42 The 2010 Amendment was silent as to retroactivity, and hence bore "no clear legislative intent that the Amendment should be applied retroactively."43 Moreover, Kia's rights under its preexisting Dealer Agreement with Glassman were vested rights, as they were contractual rather than statutory.44 Finally, the Sixth Circuit held that the amendment "[c]learly ... imposes a new substantive duty and provides a new substantive right that did not previously exist," and therefore was not procedural or remedial.45

The Sixth Circuit recognized the retroactivity issue presented by these circumstances, contrary to the Court of Appeals below, which undertook no retroactivity analysis whatsoever. We find the Sixth Circuit's analysis and application of Michigan law persuasive. Accordingly, we hold that the pre-amendment six-mile radius that was in effect at the time Chrysler and LaFontaine entered into their 2007 Dealer Agreement governs that agreement such that Chrysler need not show good cause for the establishment of IHS's proposed dealership location.

IV. CONCLUSION

The Court of Appeals erred by limiting its analysis to whether the 2010 Chrysler-IHS Letter of Intent constituted a Dealer Agreement within the meaning of the MVDA. While we agree with the Court of Appeals that the 2010 LOI created no substantive rights with which application of the 2010 Amendment could interfere, Chrysler's 2007 Dealer Agreement with LaFontaine did create such rights. Retroactive application of the 2010 Amendment would subject Chrysler to greater burdens than those in place when the 2007 Dealer. Agreement went into effect because it would require Chrysler to show good cause for the establishment of a broader geographical range of dealerships. Likewise, retroactive application would grant LaFontaine greater substantive rights than the 2007 agreement, allowing LaFontaine to challenge the establishment of dealerships that it previously could not. Accordingly, retroactive application of the 2010 Amendment's nine-mile relevant market area would impinge upon Chrysler's rights under its 2007 agreement with LaFontaine. Because nothing in the language of the 2010 Amendment evinces the Legislature's intent that the amendment apply retroactively, we decline to give it retroactive effect. We therefore vacate the judgment of the Court of Appeals and remand this case to the Washtenaw Circuit Court for reinstatement of summary disposition in favor of Chrysler and IHS.

YOUNG, C.J., MICHAEL F. CAVANAGH, MARKMAN, ZAHRA, McCORMACK, and VIVIANO, JJ., concurred with MARY BETH KELLY, J.