^ Quattro ones are too small afaik, unless they're from an S4.
JCB: surely it depends if you want the larger (stronger) inner CV joints? Maybe your method would be fine if your just running a stock motor, but if your sticking 400hp thru it, i'd suggest the larger joints are a nice to have, and Audi clearly thaught the same which is why the FWD and S4/RS4 has the larger flanges/CV's
I have a set of FWD V6 flanges i pulled out of a FWD box before i scrapped it, open to offers if you want them.