I have a Gen4 now w/ Roe H/F cats and Corsa and I think it sounds good. Not loud at all at cruise, but when you go WOT it screams.
I had an '06 w/ just the Corsa and it sounded way better than stock, but with the stock cats it obviously was not as loud as with the high flows.
Not sure if I can e-mail it to you, but I have a short vid my bud took of me at the strip a few weeks ago on his I-phone. Basically it shows me doing my burnout, but it may give you an idea of what the high flow cats/Corsa sound like. I'm willing to *try* to send it to you if you'd like to hear it - e-mail me
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