Anyone know the offset for wheels on a C5 S6?

[AndyS6Avant]

I've got the wide-bodies S6 and want to put bigger wheels on it, anyone know the correct offset, and rim width?

Ta

 

[a6george]

8J and et 35, I have a wide bodied a6 4.2 with the huge front brakes, my wheels run within 5mm of the caliper at one point, so you cant go any bigger offset than 35.
George