I have to drop off my car at the shop tomorrow morning, and I'm hoping they can give me a ride to my office. The shop doesn't have a courtesy shuttle per se, but I know one of the guys there sometimes gives rides to customers dropping off their cars. Is it appropriate or expected to tip the driver? I'm not being stingy and I'd be happy to tip him, but I don't want to awkwardly hand him money if that isn't normal. What do the etiquette gurus say?