I DD a 2006 A4 2.0T Quattro avant for 7 years with 77.8k miles now. It's automatic with stage 2 mods and coilovers for over 5 years. This car is seen on track twice a year and no mechanical nor electronic issues.
Audizine.com is a great board to start.
2013 550i M Sport
Gone but not forgotten:
2006 2.0T A4 Avant, 2007 Z4 Roadster 3.0si, 2006 M Roadster