Is your name on the title at all? You may have (slightly) more leverage in that case, but co-signing any loans is not a good idea, even for a friend or relative. As this article notes:
Generally, co-signing refers to financing, not ownership. If the
primary accountholder fails to make payments on the loan or the retail
installment sales contract (a type of auto financing dealers sell),
the co-signer is responsible for those payments, or their credit will
suffer. Even if the co-signer makes the payments, they’re still not
the owner if their name isn’t on the title.
The Consumer Finance Protection Bureau (CFPB) notes:
If you co-sign a loan, you are legally obligated to repay the loan in
full. Co-signing a loan does not mean serving as a character reference
for someone else.
When you co-sign, you promise to pay the loan yourself. It means that
you risk having to repay any missed payments immediately. If the
borrower defaults on the loan, the creditor can use the same
collection methods against you that can be used against the borrower
such as demanding that you repay the entire loan yourself, suing you,
and garnishing your wages or bank accounts after a judgment. Your
credit score(s) may be impacted by any late payments or defaults.
Co-signing an auto loan does not mean you have any right to the
vehicle, it just means that you have agreed to become obligated to
repay the amount of the loan. So make sure you can afford to pay this
debt if the borrower cannot.
Per this article and this loan.com article, options to remove your name from co-signing include:
- Get a co-signer release
- Refinance, consolidate, or modify the loan
- Sell the asset and pay off the loan
If you're name isn't on the title, you'll have to convince your ex-boyfriend and the bank to have you removed as the co-signer, but from your brief description above, it doesn't seem that your ex is going to be cooperative. Unfortunately, as the co-signer and guarantor of the loan, you're legally responsible for making the payments if he doesn't. Not making the payments could ruin your credit as well.
One final option to consider is bankruptcy. Bankruptcy is a drastic option, and you'll have to weigh whether the disruption to your credit and financial life will be worth it versus repaying the balance of that auto loan. Per this post:
Another not so pretty option is bankruptcy. This is an extreme route,
and in some instances may not even guarantee a name-removal from the
loan.
Your best bet is to contact a lawyer or other source of legal help to review your options on how to proceed with this issue.