Depending on the agreement you could go take the car back otherwise you could sue them for possession.
This is just my opinion and not a comprehensive answer. You assume the risk because this answer may not apply to your situation depending on the facts.
This is quite a problem. Your loan company most likely will not let you off the hook and you'll be
still responsible for car payments. If the company repossesses the car, they will probably
sue you for the damages. Therefore, you will need to bring an action in court to regain possession of the car and sue for damages. This is a complicated and expensive process designed for car loan companies rather than for inviduals.