See also:

Automatic deactivation during forward travel
The system switches off when a certain driving distance or speed is exceeded. Switch the system back on if necessary. ...

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

Switching on the rear window wiper
Press the lever forward: intermittent wipe. When reverse gear is engaged, the system switches to continuous operation. To clean the rear window, press the lever further forward. ...