Mechanics work on your car for a few hours and the job is done forever.

Haaaaa story time.

Had a flat. Not a big deal; got the spare on, schedule some time at the mechanics to get a new tire. Tire gets put on, everything is great, time passes.

Later, come back for a regularly scheduled tire rotation. "We can't get the lug nuts off. They've been over tightened." the mechanic says. "Well, how do you suppose that happened?" I ask. Of course, it goes a. completely over that their head, (they were the last ones to touch the lug nuts) and of course, b., it's my wallet that pays for their error.

They were not the mechanic for a while after that. Aside from that gaffe they did good work, and everybody else I tried for a while was all around worse. Eventually returned to them, and that was really the only problem I ever had…

...unless it's a GM