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

See also:
Contacts
...
Switch off the engine during longer stops
Switch off the engine during longer stops, e.g.,
at traffic lights, railroad crossings or in traffic
congestion.
Fuel savings are achieved after the vehicle is
switched off for only approx. 4 s ...
Switching on/off manually
Press the button.
On: the LED lights up.
Off: the LED goes out.
The PDC is shown on the Control Display.
Switch on the backup camera via the iDrive. ...
