Shot a quick video - Crappy video quality.. but we literally had 5 minutes to shoot and we just wanted to grab some audio. The audio is fairly decent - so it's worthwhile to watch.
Active Autowerke on my M5 - BADASS setup. Fitment wasn't great, but there is no better sounding exhaust on the M5.
I bought the Akro for my M3 from Cal at Sonic. He's been great to work with - highly recommended.