Ditto the above... Contact a lawyer, I you have any documentation or a signed work order, have it handy. You cannot just go on his property and get it. He can turn around and say that you haven't paid him for the work done, and place a mechanic's lien on your truck.
Maybe the simple thing to do is to stop in and see the shop owner, write him a check for the work done(or cash, get receipt), and be prepared to take your truck right there and then. Bring along a friend and a flatbed. If you go in there all sorts of pissy, you'll get the same in return. Good luck and keep us posted...
Andy
