Correct me if I'm wrong, but I thought BAS was different to the brake-by-wire system (Sensotronic) in the E and SL classes. I've even got it in my C-class, and I believe it is still a mechanical connection between pedal and brakes. When it detects emergency braking, it applies maximum braking force (even if the driver inadvertantly lessens pedal pressure)resulting in shorter stopping distances.