https://www.bmwblog.com/2015/08/27/introducing-the-bmw-m-performance-exhaust-system-active-sound/
Introducing the BMW M Performance exhaust system Active Sound
Aug 27, 2015 - BMW is now offering the BMW M Performance exhaust system Active Sound with a new complete system comprising exhaust, sound system and control unit
bmw m performanceexhaust systemintroducingactivesound
https://www.bmwblog.com/2011/02/19/new-m-performance-exhaust-for-bmw-m3/
New M Performance Exhaust for BMW M3
Feb 19, 2011 - BMW today announced a new M Performance exhaust system specifically designed as an accessory for the BMW M3 Coupe, Sedan and Convertible.
m performance exhaustnewbmwm3