Check out DriftWorks Phil Morrison in his V10 powered BMW M3, the sound is pure porn especially since the Exhaust Valve is open to bypass the silencer. Plus there is the added bonus of some over run flames.
Video Description:
Taking a moment away from his sideways life, Phil takes his 545bhp V10 powered E46 M3 to the Nurburgring. With the exhaust valve open the car measured 130db on a flyby down the main straight.
The exhaust valve in the video is available from DriftWorks.