My ex sold our car that still had money owed
This is not a finance issue, it is a legal one.  You need to talk to a lawyer. To save your credit you can pay off the bank now and fight out the details with your ex later.  The bank is still owed their money.
Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
My ex sold our car that still had money owed

### Response:
This is not a finance issue, it is a legal one.  You need to talk to a lawyer. To save your credit you can pay off the bank now and fight out the details with your ex later.  The bank is still owed their money.