RC:
noone1:

It's the 540hp  that has always been out, and the normal version can already put most of the powee to the rear, so...

V10 engine in 42 and 4S don't share a single bolt, the engine has been completely redesigned to be used in the LMS race car, so a re-built every couple of dozens racing hours isn't necessary anymore (cost saving and reliability).

Are you saying the Audi RWS uses the engine from the last gen R8?

I'm saying that there is probably nothing of interesting to say about the R8 RWS since it's just a normal R8 with less power. It has a little less weight, little less power, and the normal AWD model can already put most power to the rear wheels anyway.