well...I like oem stuff...the calipers on 2006 A6 quattro S Line are huge. I decided on a Euro spec 19x9 with 255 - 35 - Pirelli P Zeros. I am happy to report that the performance from an 18 inch RS wheel to the 19x9 is shocking. I have never made a wheel change that had such a drastic improvement in response and handling without sacrificing the ride comfort. Here is what i discovered...I had squeaky brakes and slow rolling to a stop was at time painful! With the wheel change, I have not experienced a single squeek! (knocking on wood now) I attribute this to larger area and air flow and possibly reducing dust. I also feel the forces of the larger wheel may play a factor. I just wanted to share my thoughts.