Honestly, the best you can do is to avoid frequent short trips where the engine doesn't reach operating temperature and to frequently redline to get the engine real hot to burn the crap off and blow it through. Having said that, I did have a cold start misfire on cylinder 6 at around 16,000 miles and the dealer peeked into the engine and saw minor carbon buildup on that cylinder. Audi told them to drop two cans of BG44K into the tank and instruct me to drive the car hard for 50 miles, so I did. Haven't had a misfire for the past 5000 miles.
'13 panther blk RS5, Ti pkg, blk leather/alcantara, nav pkg, sport exhaust, driver assist pkg, rear shade, alu kreuz, ECS spacers 15f/10r, ECS tru-float rotors, ECS brake lines, Hawk HPS pads, european delivery
'07 phantom blk S4, blk leather, 6mt, conv pkg, audio pkg, heated front&rear seats, bluetooth, nav plus, parktronic, DTM pkg, carbon trim, TPMS, rear&side shades (sold)