My ZHP seems quieter than I remember my old one being, so I'm wondering if maybe it had a 325 exhaust installed at some point. Or maybe I'm just used to the insanity of the S54 with a CSL rep intake.

Looking under the car there's no evidence of the exhaust flap, so it's at least probably not a 330i exhaust, but I don't know how to tell between the 325 and ZHP muffler