I have heard numerous horror stories from Audi owners. Even the legendary TDI engine in its 170bhp format is hugely problematic in the Audi A4 installation but unproblematic in the Skoda Octavia installation(apparently completely different oil pump set ups).
I test drove the original Audi TT. It was one of the least involving cars I have ever driven, just felt completely sterile and devoid of feedback. Again strangely, the same engine and brake set up in the Skoda Octavia vrs and Seat Toledo 1.8t Sport works really well. Other than understeer issues, these cars were really good driver’s cars.