If you purchased a vehicle and you believed that you qualified for the $500 rebate and have signed documentation by the dealer and yourself showing that you are entitled to this rebate, you should be entitled to it in that had you not received the rebate, you might not have purchased the vehicle that you did.If the error in giving you the rebate was an error by the dealer and you did not realize that there was an error until after you had purchased the vehicle and driven it off the lot, then the error is something the dealer needs to absorb not you. The error was an unilateral error on the dealership's part.