I had the Gintani race + catless xpipe. Low RPM's have a low rumble, and from the outside I can understand where people think it sounds like an American V8 (inside the car this isn't the case). Once you go past 5k rpm, the thing sounds exotic and like a monster. Definitely not American, inside or outside the car.
2009 E92 M3 | Alpine White | Black Extended | Advan RS | Turner Test Pipes | Dinan Axle-Back | OETuning | Eibach Springs | UUC SSK | VRS Front Lip | VRS Type I Diffuser | Matte Black | RPi Scoops | MS Filter | Yokohama AD08 | F1 Pinnacle
Special Thanks: Gintani | OETuning | eAs