BMW 325i. Man!! That thing is fxxking loud. He has BB triflow catback exhaust. The noise is so annoying. Sounds just like a straight through pipe from header to the tail. Totally kill the sound of the car. I think NA should have atleast some sort of catalyst converter. In the case of turbo, my car has gutted pre-cat and DSP test pipe, and Greddy SP catback system. The noise is deep and low bass. Not too loud and not too silent. Just nice.