The concept
The parking brake is primarily intended to prevent the vehicle from rolling while parked; it brakes the rear wheels.

See also:
Applications
Please try the system first during sparse traffic
and clear road conditions so that you can get
used to the system. After you have experience
and understand the system, only then use it during
...
Dynamic, efficient and innovative: the new BMW 3 ActiveHybrid
In autumn 2012 a further model will join the BMW 3-Series. In the new 3
ActiveHybrid - a full hybrid at the premium end of the sports sedan class - the
innovative BMW ActiveHybrid powertrain techn ...
Terminating the voice activation system
Briefly press the button on the steering
wheel or ›Cancel‹. ...
