Two of our "best" were also the "worst". One was a 2008 Toureag. The V10 diesel, which was pretty exciting in terms of the 550 ft/lbs of torque. Other than that, much like Jed's experience. It was not a great driver, much as I wanted it to be. The newer ones seem lightyears better. Very glad to have an extended warranty, and it frankly helped when we sold it as when you pulled up the VGA service records on line, they were scary. Owned it for about a year and half, and we went back to our go-to, a Land Cruiser. Polar opposite in reliability.
The other nightmare that we loved was a 2003 W8 Passat wagon. When it was at it's best, it was tremendous. Perfect size for me. Great driver, and awesome in the snow. A real sleeper, it had a lot of guts. And, I would not be surprised if it set the high bar for VW warranty repairs. I had a 100K warranty on it. The engine came out of the car three times, and was replaced once. Two transmissions, I think four clutches. More significant electrical issues that I can recall. And on warranty, the answer was to just replace! During the last six months that we owned it, I just wanted to get it sorted out to get rid of it. One of my close friends was the dealer, and he set me up in a GTI as a loaner. For 16K miles! When it ran......it was great. Interstingly, despite all of the problems over 80K miles, I never was stranded and never had to haveit towed.
Thank goodness for small favors. That car flipped my reliability switch, go the next car was a CPO Subie Legacy GT wagon.
Having the W8 and a problematic S6 at the same time was not a great time. Thank goodness we had a Landcruiser as well.