Suing to get a car in my name back, and back payments

I bought a car about 2 years ago, in my name solely, for a friend with the verbal agreement that he would make the car and car insurance payments every single month (he really needed a car and did not have the credit to put anything in his name). Over the past two years he has only paid me a total of $2,493, but still owes me $7,817. Two weeks ago I told him that I wanted the car back or else I would report it stolen. He did not give it back, and the police said I needed to sue him to get the car back. The few questions I need answered are: 1) How do I find him. 2)What if I can't find him to inform him of the suit because I don't know where he is. 3) If I do find him and take him to court, I know I will win the car back, but will the verbal agreement hold up in court? The only evidence I have that he agreed to pay for the car are some text messages saying different things that would indicate his knowledge of financial responsibility, and the money transfers that he made into my account every once in a while.

If the car is in your name, take the title, registration and car key and go get your car.

I don't know where the car is, I think he lives in Texas, but I'm not sure.

Q -1) you've made it this far, try online searches for him. Otherwise private investigators work with repo. men all the time.
Q -2) your local sherrif is often used to deliver the summons, if the person has not been served within your state's time frame, a certified letter, or a sherrif in the county he resides in may do the trick. Some states may place a warrant for his arrest, if they find him in contemt. If the defendant has not been served (in my state) after 1yr, you get a default judgment for the full amount.
Q -3) Bring all your evidence (text msg., cancled checks, bank statements, etc...)
This will show his intent, and your good will.
No Doubt You Will Win!