As a Franchise Attorney I advise you to read your contract carefully. Usually (and I'm assuming the late fee is for not picking up your purchase yet) if there is a late charge for not picking up the vehicle by a certain date, it is specified in the contract or a notice is posted at the dealer's business. If neither was done, then you should have grounds to complain. Consult with a good business or franchise attorney in your area for specific advice.
Mr. Franchise - Kevin B. Murphy, B.S., M.B.A., J.D.
Franchise Foundations, a Professional Corporation