If the car was not a certified pre-owned (CPO) when sold to you, you could likely do one of  the following: rescind the contract (give the car back and receive your money back--though after a year, this might not be an option a court would favor); receive compensation for costs you incurred which you would not have had the car been properly CPO (e.g. excessive servicing costs); or "reform" the original contract so you receive back some of the purchase price (difference between CPO and non-CPO car). The theory would be that if the dealership knew or reasonably should have known the car was not CPO but misrepresented it as CPO, that was fraud; or if they did not know, then you and they were both affected by a "mutual mistake"--the agreement of sale was incorrect, in that they were not selling, and you were not buying, what you thought you were. Either theory can provide a basis for recovery, though if you can't work out some compensation voluntarily with the dealership, you'd need to sue to try to vindicate your rights.