Originally Posted by Martin_D
It is the brake boost assist. This happens to fast drivers in the E9X M3. The system pulls vacuum from anywhere it can and you get an inconsistent pedal.
AE performance is working on a fix for this. It happened plenty of times in my car, happens with their car as well. Anyone driving fast knows about this.
Then I guess Im going slow -- cause Ive not had this issue -- but good to know that there IS an issue with the brake boost