Love the RS7, wish I can get that car later down the road.
Technically, Audi has Stasis, which is equivalent to Dinan for BMW. Yes, Stasis provides warranty for their performance products, same warranty concept as with Dinan. I can go to my local Audi dealership to get Stasis parts since they are authorized Stasis dealer.
Personally, after trading my E90 335i for a B8 S4, the S4 blows the 335i in a lot of categories. I agree 335i is a driversí car and focuses on performance. However, the S4 has a better interior, more refined, and itís fast car as well. Having AWD is a bonus for me. I donít think you can go wrong with either car, but for me the S4 is the better overall package car.
Itís funny how in this review they say BMW has the better interior but Audi has better performance. Fair review and Audi has stepped up their game.