See also:

Visual warning
The approach of the vehicle to an object can be shown on the Control Display. When the distance to an object is small, a red bar is shown in front of the vehicle, as it is in the PDC display. ...

Front
Front Slide the cover back. ...

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 ...