I averaged 16 ish MPG in my RS4, only getting 21 in the RS3, however most of its driving is town and school run with my wife
The RS4 was a phenomenal car, very competent in all areas's, except economy. Ive only driven an M3 round Brands, which was nice, but the RS always felt more special.
I think I just like the safety and usability of 4wd, without get a 4x4 (if that makes sense). My Kombi is 4 motion