See also:

Switching on automatically
With the engine running or the ignition switched on, shift the selector lever into position R. The image of the rear view camera is displayed when the system has been switched on using iDrive. ...

Switching on/off
Press the button. ...

Priority options
The driver has priority The source selected via iDrive in the front is output on the vehicle loudspeakers and can be selected but not operated from the rear. Other audio or video sources ...