This is a tough question because there are so many things to think about. You really need to ask someone in your state with legal knowledge. Let that one ask you the details and answer truthfully. A person who co-signs a loan takes a big risk and also has a lot of rights. If the owner can't negotiate privately and get a good result, he may need to go to small claims court and let a judge sort it out. Think about whether the owner has made all the payments, possesses the car, if the refinance was legal. Now, if both names are on the title, there isn't one owner but two. That means there isn't a co-signer, either, but two signers for a loan on a car they both own. This gets pretty tricky. Here is a bit of advice that is too late for this case, but may help in the future: NEVER co-sign a loan because it's rarely anything but trouble. If you can't get a loan without a co-signer, you probably can't afford the car. Buy a piece of junk for cash and then save money to buy a better one. There may be marriages made in heaven, but signer/co-signer is a marriage made in hell, as you're finding out now. Sorry i don't have better news for you. The good news is that life goes on. You will survive this and it may be an inexpensive education. Best wishes.