As far as cars go, I had an Audi, 1998 A4 2.8 Quattro manual transmission.
Here is what went bad, as per my memory...
At 38,000 miles, the transmission went out. Started making bad noises, took it in and the dealer took 30 days to fix it. I had a 1999 A4 Avant as a loner. Not bad...
Then at 51,000 miles, SAME THING. The dealer pro-rated the repair so it was about $300 out of my pocket. Seems they didn't follow procedure.
Then at 60,000 miles one of the 4 O2 sensors went bad. That was $120 out of my pocket to fix BUT I had the little Vag Com tool to do the complete scan. And I had the Bently (factory) manual. Vag Com is a tool you use with your PC to diagnose Audi/VW/Seat/Skoda vehicles. The regular scan tools work BUT the Vag Com tool works JUST LIKE THE FACTORY VAG (Volkswagon Audi Group) TOOL AT 1/10th THE COST!
At 78,000 miles, an errant drunk ran a red light and tore the front end off the car, killing it and nearly me in the process. He was going 70+ MPH at time of collision. After tearing off the front end (and half the engine), the other car veered into the median, hitting a curb and flipping end over end 3 times, coming to rest on its roof. The other guy didn't make it. But I did..
Now, where to get this elusive, must-have for the shade-tree Audi/VW mechanic? On line, of course!
No, I am NOT associated with Ross-TechYou can do SO MUCH MORE with the Vag Com compared to generic OBDII scanners. For instance, you can reprogram your windows so the key remote will roll the windows down with a press and hold of the unlock button (only on Audi, NOT VW...THEY ARE NOT THE SAME LINE!) Or you can disable/modify the locking alarm chirp/flash. And it is far easier to reset the oil change interval reminder with the Vag Com...among the 1000's of other things.
I say get a Vag Com.