In Washington state, most property acquired during marriage, including a car, is community property.  Many states have similar laws.  If your name is the only one on it and you are separated, you could just go and take it back when he's not around or call the police and report it - "my ex-husband stole my car; it's in my name only."  If you take or get it back, you might consider getting one of those anti-theft bars to put on the steering wheel or some other anti-theft device so he can't just take it back. You may consider filing for divorce or legal separation and asking the court to immediately award you use of the car.