I would sell her car.

You might say that sounds drastic but she has been late on a payment and it hit your credit. If your name is still on the title, you can possibly sell it. You would be violating a court order and you would need to consider the ramifications of that. I can tell you that in the almost 6 years that my divorce has been going on, my to-be-ex has violated many, many court orders with ZERO repercussions. She even embezzled my company truck from my separate property business, sold it and I could do nothing. Check with your attorney first might be a good idea.

If you have no real attachable assets like a house, you are in an even better position. You might want to make sure her name is not on your car if it has any value above the loan.