RS3 with 4.2V8 i cannot see how myself, Different engine layout for a start.
Maybe an even more powerfull ~300bhp 2.0T but i have a feeling more than likley a VR6 turbo like the cars VW showed at SEMA were equipped with if it ever happens, It could of cause just be Audi playing the media game like Ford does about the Focus Cosworth. lol.