Would love to hear some more feedback on the "growl". I run my 08 E90 (pretty much stock except for wheels/tires/brakes) in HPDEs and I cannot hear the engine at all. So, I was thinking about going this route myself, hopefully to keep me off the rev limiter. What does it sound like at 6000 RPM? Could I hear the growl at 120MPH
in fourth gear with the front windows open?