When you get on it the noise difference is there. Also remember this a BMW which has good noise isolation from the outside. I didn't think mine was even noticeable with just regular driving until I had a friend following me who has a 3.0. When we arrived at our destination his first comment was about how bad ass the exhaust sounded.
I have also had a cop comment saying I had a modified exhaust and a loose nut behind the wheel.
