I have an '96 A4 1.9 TDI (if anyone wants, give me a shout), and just bought an 2001 A6 Avant 1.9 TDI. Love the VAG TDI engines, rock solid. Been impressed with Audi's overall. My A4 has needed hardly any work for an 11 year old car. Can't fault em :)
Anyway, got a slight issue, so better get posting :)