Being an auto mechanic takes thousands of dollars worth of tools in order to advance beyond doing tires and oil changes.

Also, it doesn't resist recession the way out outsiders think it does. In times of good, people get rid of their absolute wreck to buy a decent used car at the same time people buy new cars. In addition, people hanging on to older cars tend to ignore maintenance, and have tires that are on the verge of catastrophe. That, and anyone with no warranty will avoid repairing their air conditioner, stereo, or other extras until good times return.