ET 35 will fit your car, come mighty close to your calipers but do fit, I have et35,s on mine.
any thoughts on the tyres? I run my C5 on 18's in the summer and prob goint to swap back to original 16's for the winter with Dunlop SP Winter Sport
A6 Avant 2.5tdi Quattro Sport 220bhp 458Nm 6 speed Manual