“People get this confused all the time. A cosigner is simply a person who pledges to pay off a loan if you, the primary loan holder, can’t or won’t.
They have no legal right to the car, as their name isn’t on the title. Could your stepfather report the car as stolen? He could try, I suppose.
But in most cases, the authorities will want to see his name on the title to know that he is the rightful owner of the car. Since he can’t procure this document with his name on it, chances are that nothing will happen.
If your car is reported stolen, just stay calm. If you’re pulled over, explain the situation to the police officer and they’ll sort it out within the law.”