Apologies to you personally TheUnforgiven, but....
I worked at a Plymouth stealership in the late 70s and we saw some INCREDIBLE damage done to the higher end Chryslers by hamfisted GM trained mechanics in the town over from us.
These tools would hammer the $300.00 wire hubcaps onto the rims with rubber mallets, making nearly every spoke rattle on brand new R-bodied Fifth Avenues ($26,000.00 cars back when a Nova was $6,000.00).
This didn't happen just once and it didn't stop after the owner and service manager contacted the Chev-a-lay stealership and notified them. One of them rolled back to us with so much bathtub caulking in the spokes the wheels wouldn't balance ! (their GM answer to un-F@%&ing their hammer work).
It even continued after one of the NewYorker owners, a lawyer, sued their @$$es off in court and the judge reprimanded "the primitive installation methods" the dealership used. That went over in the pits in a big way !
These neanderthals actually ruined several A-arms trying to remove ball joints by pressing them out !!!!!!!!! Any mechanic I know, understands they screw in, just like every NASCAR ball joint (because they use superior Mopar design ball joints, even on GM nascars). Who-TF rivets on a wear item !?!?!?!?!? or welds on door hinges !?!?!?!?!
I got a call one day from one of them asking where the points were on a 74' Dart Sport 360. I couldn't believe I was answering him but I said "good lord man, we haven't had points on ANY of our cars since 72'.
They f#@&ed up a torsion bar(which ALL GM trucks finally adopted 20 years late BTW) removal so bad we had to get a welder in for the customer (after he had it towed to us) to re-do the frame !
So, I'm sorry if I included you in the ring of "hacks extraordinaire" TheUnforgiven, but......most every hack mechanic I've encountered was GM trained.
Sort of like "not all Muslims are terrorists, but all terrorists are Muslim"
Sixlitre (politically incorrect, as usual)