The old A4s were really solid and well built. My friend had a 98 base model, no issues, and she survived some guy in a huge SUV cutting her off because he was going to miss his exit, he clipped her front corner, his SUV rolled several times, he died in the accident and all of his passengers were injured, my friend's A4 was totaled but she walked away with a few bruises from the seat belt. She had 2 A4s after that and didn't like them as much.
I think Mimo raises a good point by comparing car ownership (especially German car ownership) to watch ownership. The more complications the piece has and the more an owner might pass up routine or needed maintenance, the more "unreliable" it becomes. Not to imply that's the case with any gents present, but certainly food for thought.
My friends that had issues with their cars had them while new and under warranty. Nothing out of pocket at issue. Some just felt Audi didn't stand behind their products as well as they should have.
I've never heard of an partial overhaul with any of the watch companies. The only thing I've heard of as extra that can be opted out of is polishing the case and bracelet. If the watch is relatively new they might simply regulate it. If its say a year old or more, I think they will tell you to send it in for an overhaul or live with it as is until you want to overhaul it. Certainly if you hear differently let us know.
A friend had an R8 V10 and 2 Porsche 911s. He said overall the R8 was really nice and had great performance, but for better or worse at that kind of money its an Audi. Once you are in that kind of price range you can drive something more exotic and more exciting. After 2 years he traded it for an Aston Martin Vantage with a V12...now that's a car he really loves...and he kept both 911s.