What? Nobody's yet mentioned the RS5? Oh, yeah, you wanted four doors.
Still, it's something I'd consider if you can wait until it comes to the US. (It is coming, isn't it?) The S4, even though Audi's done a good job of masking it, is still too nose heavy. Perhaps it only comes out during very "spirited" driving so maybe its not a very valid point. Good luck.
Cheers.