Well the Q4 finally spat its exhaust out of the back just before Christmas so it looks like the next expense has just arrived. Anyone know if there are any suppliers who supply these or is it as I expect a custom made job ?

Looking on the Integrale and Fiat coupe forums it looks like a 2 1/2" stainless system with removable "cat" and twin DTM style back box may be the best to go for as it should fit with out the grounding issues of a 3" system.