See also:

Buckling the belt
Buckling the belt Make sure you hear the latch plate engage in the belt buckle. ...

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

Enabling operation in the rear
Only possible via the iDrive in the front. 1. "Settings" 2. "Allow rear control" 3. Select the desired priority. ...