Dennis, I have to agree with Rearn2go72. You can do a lot of getting even stuff that would make the SOB regret, and change his attitude. Place an add in the local paper, make a complaint to the BBB, go to small claims court. And the best one as far as I'm concerned, put a lien on his property. That screws up his credit and get his attention big time, but get your car out first.

I don't think you could file a lein on his property for something like this. It would be different if you did some work on his building  like a roof or something and he failed to pay. The real problem here is he has an estimate and a receipt for his $5,000.00 check. There was no completion date agreed upon or in writing. I don't know if a claim would even stand up in small claims court. All the body shop owner would have to do is show documentation that he has already done $5,000.00 worth of work on the car and it would be thrown out. Maybe there would be a way to get him blacklisted from the insurance companies though. Lawyers are very good at digging up dirt to make the guy feel a little pain.

at least send the complaint to the Better Business Bureau. They really follow through. It worked for me

Luke

 I also agree with Luke, I have also used the BBB and it does work, puts a mark on their record. 

He said the insurance work comes 1st. Make sure you call the insurance companies to let them know what a reputable business associate they have.
Small claims court is correct process to retrieve any $$$ that are tightfully yours and you should pursue this avenue.
Newspapers and ads are fine depending on your status but I would refrain from using this manuver there are better methods to contribute to his business.
I wouldn't hesitate to inform local car clubs etc. Word of mouth can be very powerful. As an example I saw a car this summer at a car show with a full blown 3'x5' posterboard complete with pictures detail shoddy interior work done on a convertible.
It seems the fellow had a bad experience such as you and he detail every item complete with the shops name, estimate and final bill. He also had a sign inside the car advertising the shop who completed the work.
Over 1200 people attended and viewed this car. What kind of results do ya think this got both shops?
Need I say more?

  Thanks for all of the replies.  I am very P.O. at this guy for this nonsense. I am going to make an appt. with a lawyer first to check all the available legal options that I have. Its tempting to consider some illegal ones too.

But I do have scruples. I like the poster board idea. The town has a big 4th July parade. Maybe I should drive it unfinished in the parade that would have some impact.