About the $45 Avenger 3rd brake light bulb: the late '80's Buick Century had the turn signals in the front bumper. The bulbs were replaced from the rear, but you could NOT get the sockets out to replace the bulbs unless you removed the front bumper cover and then took the light out of the metal bumper bar. That one legitimately involved a labor charge for that reason.
I got cussed out by more than one little old lady who just could not understand why it took an hour and (at the time) $70 to replace a bulb. When doing one of these the techs would use a hole saw on the rear of the bumper so the socket could be removed easily the next time. Probably screwed up the crash safety, but what are ya gonna do?
mad_machine, many VW's from ~1994 on had a data link from the radio to the engine control unit. It allowed the VAG 1551 to perform radio diagnostics and also if the car was equipped for the speed sensitive volume it was the data link for that. This wire looked exactly like a ground wire and would, if you tested it, actually complete a ground circuit. If that wire were improperly used, not only could it fry the ECU and other control units but it could blow up the test computer! One of many pages on this problem: http://www.ross-tech.com/vag-com/aftermarket-radio.html
There was a VW tech bulletin which stated that if the factory radio plug were cut off to allow installation of an aftermarket unit, the car's warranty was presumed to be void. As in: if a car came in with a driveability concern and the plug had been cut off, all bets were off.
If a plug from a company such as Metra, etc was used, to plug into the stock harness, then all was well.
We were expected to enter that information (cut or not) into VW's database for other dealers to access. If we did not, and another dealer damaged their VAG it was quite possible they would expect our shop to repair it.
Due to the possibility of damaging the tester, it was necessary to remove the aftermarket radio to verify the connections before plugging the computer in. VW would not cover this as part of a warranty repair and the techs expected to be paid for it. Man, did THAT create some friction!
Now just about every manufacturer includes that data link in their harness, so cutting the harness to add a radio to ANY new car is NOT a good idea.