RS246.com Forum :: The World's #1 Audi R, S and RS Enthusiast Community

Finally found one that is up to date and includes the RS4 (Audi USA parts sites don't for obvious reasons):

https://ifinterface.com/prog/car/cp2/inprog.php

Bit clunky to get around but it works. You need to double click in places to select a parts group and proceed, or open an info popup on a particular part.