These comments are made for educational purposes only and do not constitute legal advice. No attorney-client relationship exists between us.
Going to the shop and trying to remove the truck would not be a good idea. You could find yourself charged with trespass. Because some work has been done the shop owner could assert a mechanic & materialman's lien on the truck. If you tried to take it you could be charged with attempted theft. Send a letter by certified mail demanding return of the truck. If that doesn't work, you may have to sue.