I had wanted some CMS C8's after seeing a guy on another forum on his R32. He ended up taking them back cos of the rubbing.
His were 8 x 19 ET45 with 235/35/19 tyres. The alloy wheel shop wouldn't sell me them unless I took the risk. They said that even though an ET45 was for the Golf mk5 it was wrong.....
7.5" x 18" ET51 with a 225/40/18 tyre = correct clearance.
8" x 19" ET45 with a 235/35/19 tyre = 24mm further out.
Also you need the 235/35/19 tyre to get the correct loading. I have read threads were in the states they run a 215/35/19 tyre. Something they call stretched, they do look odd though..... highly illegal in this country I would think.