If no representation was made about the vehicle, or it was sold "as is" then there is no obligation for the seller to take the vehicle back but if that is what the buyer and seller agree to do, then the payments are probably cancelled since you are cancelling the sale itself. Buying a car in a private sale can be risky business because the law is very different from a car dealer sale. In a sale between two individuals, neither of whom is a car dealer, in most states the only obligation on the seller is to answer your questions honestly and not hide anything that they realize you would want to know about. They have to tell the truth about the mileage on the car too by filling out correctly and honestly an odometer statement for the buyer. And in those states that require mandatory emissions tests in order to get a vehicle licensed, many of those states say that if the emission/pollution equipment was disabled or removed then the buyer may have the right to cancel the sale. If none of that applies to you in your deal, then you may be stuck. You need to talk to a local Consumer Law attorney. Call your local attorney's Bar Association or you can go to this web site page (http://ohiolemonlaw.com/locate-a-local-attorney.html) for a free national list of Consumer Law lawyers and find one near you (lawyers don’t pay to get listed here and most of them are members of the only national association for Consumer Law lawyers, NACA.net). Also, for every legal right you have, you only have a limited amount of time to actually file a claim or your rights expire (it's called the statute of limitations), so don't waste your time getting to an attorney and finding out what your rights are. If this answer was helpful, please check the box below.