See also:

Safety switch for the rear
Press the button on the driver's door if children are being transported in the rear. This locks the rear window switches so that the windows cannot be operated from the rear: safety switch. ...

USB audio interface/mobile phone audio interface
At a glance It is possible to connect external audio devices. They can be operated via iDrive. The sound is output on the vehicle loudspeakers Connectors for external devices ▷ Connection ...

Removing the mobile phone
  Press the button and remove the mobile phone. ...