Saves your life and totals your bank account to fix it again. Crumble to absorb energy.
I'm glad I don't do body work anymore; it's all R&R now. And the paint sucks.

I worked almost exclusively with acrylic lacquer. Pretty much factory replacement for standard customer cars in body shops. I did a fair amount of side work on bikes and hot rods that involved metal flake, black pearl, red pearl and stuff like that. I could never draw well enough to add pictures to the mix. About the time I switched careers, some shops were switching to enamel. Earl Scheib always used enamel.
The old man who originally took me under his wing and taught me body work insisted that I learn to use lead and metal finish before I was allowed to use bondo (plastic filler). By the early 70s it was getting so everything was simply R&R. A lot of the time I could do a better job straightening a quarter panel that was welded on than cutting it off and replacing it with a new one and make more money at the same time. Other people in the shop bitched that I "wasn't doing it right".
I got into the medical dodge and went to work at the Cleveland Clinic.