I disagree, I almost ALWAYS see stock dual exhaust cars converted to single exhaust on larger turbo applications as they make more power. I was bugged to death about converting my old s2000 into a single 3-4" exhaust and that id see large gains. on a stock non turbo car however I would completely agree with you which is why I said it was retarded of the g35 owner to convert his stoc exhaust into a single 3"