No one has to tip anyone, ever...
But to be called an arrogant prick for suggesting you tip a good mechanic kind of rubs me the wrong way, you know?
I don't even do my own oil changes, and here in south Florida, a lot of mechanics lease their own bay space. They're not hourly employees. So I drive like 20 miles to see Charlie:
62 years old, and I trust him a thousand times more than any young shmuck working at Pep Boys for 11 bucks an hour.
Same cost for the oil change more or less...but I always throw him 10 extra bucks...and I'm being lectured that you're going to get good service and attention in Canada just because you're supposed to and that mechanics shouldn't expect tips?
I just don't buy it. It's called capitalism, and there's nothing wrong with showing a mechanic your appreciation for the job he's doing for you. For God's sake, he DESERVES it.