Is there any way to be removed from my sister's vehicle contract without having to request a voluntary repo?

I am not licensed to practice law in your state.

These comments are made for educational purposes only and do not constitute legal advice. No attorney-client relationship exists between us.

Before you can do anything to resolve this matter, you need to have possession of the car. You are entitled to possession because you have an ownership interest. So, you need to have it towed to a secured undislosed location. Then you need to have a discussion with your sister. It would be best if she would agree to let you sell the car and pay off the note. If she won't, you can try to get a loan on the car in your name alone. If that doesn't work, voluntary repo can be done. That will damage her credit and yours and you could be sued for the difference in loan value and auction price.

Either way, you need that car back. You don't know if the insurance is being paid and you don't know what kind of driver has it now. As an owner, you could be liable for injuries and property damages if you negligently entrusted the vehicle to a person you knew or should have know was a wreckless driver.