I bought a racing beat exhaust ( header, y-pipe, and two catbacks) for a n/a s4. Everything except presilencer for 100 bucks!! Still new looking as well. Anyways the header was chopped and a flex pipe was welded on. I am hoping someone can measurr there header from the o2 bung to the flange so i can see if mine is welded to stock size or how much i will need to extend or subtract from it.