Legal Question in Civil Litigation in Georgia

Assuming you can't simply go get the car (why haven't you done that?) you're dealing with a crime, so you make a police report and then seek a felony arrest warrant. Typically they will first do a preissuance hearing. If he does not return the car and the judge finds probable cause, he will be arrested.

I'd suggest a criminal complaint as a last resort. If you voluntarily gave him the car to use, he did not steal it. Judges and law enforcement may see it as a civil dispute beyond that, and not be thrilled to be in the middle of a spat (even if there is a valid complaint and he is exercising control over your property). The first step, as mentioned, is for you to go get it -- at a time when he is not around to argue. Surely, you kept a key? Additionally, you will want to take a friend or two to assist and be witnesses, but they should not be people who will start or escalate something with him. If he shows up, call the police that second and be prepared with all title and registration paperwork. That probably ends the issue as the police will likely assist you in getting the car, and keep the peace.

If you can't do that, make it clear to him, in writing, that if he does not turn it over immediately (a day or two), you will file a complaint.