See also:

Sound output
Switching on/off When the ignition is switched off: press ON/OFF button on the radio. Muting When the ignition is switched on or the engine is running: press the ON/OFF button on the radio. ...

Deleting the button assignments
1. Press buttons 1 and 8 simultaneously for approx. five seconds. 2. "OK" ...

All around the headliner
1 Emergency Request 2 Panoramic glass sunroof 3 Indicator lamp, front passenger airbag 4 Reading lamps 5 Interior lamps ...