Just bought a set of new genuine (10 miles old!) RS4 wheels and Michelin Pilot Sports 235/40/ZR/18 on 8" rims, they fit fine and look awesome on the Zenith Grey (I think.....) Not driven yet, just done, I'll be parking 12" from the kerb from now on and wifey won't get to drive it! Only issue will be the speedo being 4 or 5 % out but I can live with that.