If this thread is about screw ups while working on cars, I have too many to list.
This one sticks in my head. I was 19 and working at my first "real" body shop (you know, one with a booth and frame equipment, pavement in the parking lot) and I we were next to a Ford dealership. We did a lot of work on brand new cars, before and after customers had seen them. The quality control at Ford in those days was REAL bad so we often would fix runs and crap like that. Anyway a customer was sent over to us to paint the underside of his hood where there were some bare primer spots on the underside of the hood skin inside the holes of the inner structure. You know, the big holes on the inner structure, with the hood up you could see spots of bare primer thru these holes. Soooooooo they send the kid out there (me) to do this easy project, armed with my touch up gun I am spraying thru these holes and doing a fine job. To get a little better angle I needed to pull the hood down a little........this was a 78 Ford Fairmont and one of the first cars I had ever seen without hood springs holding the hood up. It had a hood prop rod, one problem, the rod was about a foot long way back at the hinges and VERY strong, not a flimsy thing like they use today. So when I pulled the hood down I folded it at that prop rod! FOLDED the hood, it POPPED as it folded.
With the guy standing there!
That wasn't as good as the guy pulling the GTO out of the booth and smoking the tires (on purpose) with the car shooting out of the booth into a garbage bin right in front of the owner as he was coming early to check out his car.
When I think of some of the things we did in that shop, holy cow. We had the paint mixing room covered in centerfolds, one of the guys brought in an 8mm projector and showed pornos on the wall in the paint booth, the owner was on some serious drugs buzzing around like a mad man, I found a LARGE bag of "beans" in the trunk of a car that were being hidden by one of his friends, a spare tire falling off the back of a truck after we repaired it ripping the bed all up, us taking a full on race car out of the shop and up the main street (a real busy city main street) when the boss was out of town, smoking the tires on cars in the shop until you couldn't see a foot in front of you! That place was WILD.