Legal Question in Civil Litigation in Georgia

You are stuck with the bargain you made - entering into a long term contractual relationship with a person with whom you had no legal relationship. This was exactly the risk you took. There is no "buyer" and "cobuyer" - what is important is who is on the title. Either come to an agreement on paying for it or selling it, or risk a credit problem for both of you.

Contracts are contracts and you have no right to violate them. You made a decision every lawyer would have told you to never do - buy a car with someone you are not married to. There is no such thing as a buyer and co-buyer. You are both responsible and you both own the car (and the loan).

You will either need to keep paying or ruin your credit and probably later be sued after a repossession for more money. And even once you do, you'll only own half a car. So unless you can cut a deal with him that pays off the car, you are stuck.