While folks are diligently defining for all of us what an M car is, remember that when it comes to sound deadening impacts, what imaginative individuals envision is good engine sound while in reality it will be the unpleasant drone of tire noise. Probably why they pipe in sound.
As for Bach.. I will do my focused listening in places other than cars. However, I do care about the upgraded stereo and I do hope to occasionally listen to music.. or converse.. or think. Some may wish they had pushed the car farther in the direction of track while others, like me, appreciate the compromises going farther in the direction of daily driver. Most of these cars will never see a track but hopefully many will see canyons and almost all will see a commute.
BTW.. neither the 911 S nor a Cayman R is louder than an M3 while the 1M was notably louder than all of them (
http://www.auto-decibel-db.com/). Hope they keep it at the M3 levels or less.