Out here SUV & 4x4 sales kill sedans & wagons, but hey detest SUV's. I know snow/ice racing is serious stuff. Your S4 so go enjoy.
I take it you have an Avant. The number of lights & angling would easily determine if behind the grille is realistic. That requires removal of the entire front apron and there ain't much room in there.
Perhaps you could ask the same on Audizine US or Audiworld US forums. Agreed they do some extreme stuff, but that can be excellent research on what is brilliant and what not to do. Also research any Scandinavian Audi forums for info.
Curious, where is the S4 based? Europe & Nth America, that is serious ship fees.
Trivia - drove an Audi Q8 last night. Yes, its a SUV. 55 TFSI, a mild-hybrid version of our S4. Drove OK. <4oomls, so brand new. Basic ergonomics very similar to the S4, so no problem in becoming acquainted to operate. The electronics & dash were w-a-y too much for me. I barely use S4 MMI now.
Costs less than a RS4. Q8 fun factor = <nil, so no thanks.