When I was 18, just out of high school and waiting to be drafted, I was working in car shops. The old man who ran the body shop at a Oldsmobile/Toyota/Mercedes dealership took a liking to me while I was doing undercoat work there. I was bored rigid with what I was doing, so he took me on in the body shop and taught me the old fashioned way of doing body work. I joined the union and they sent me through an apprentice program. I didn't find out until later that being a union guy working for general motors was essential to the war effort and I was unofficially deferred from the draft.
In addition I learned a trade and to weld with electric or gas and straighten frames. It's useless information now since cars don't have frames and are made of plastic and disposable panels, but it was fun at the time.