See also:

Adjusting the volume
Turn the knob until the desired volume is selected. The setting is stored for the remote control currently in use. ...

USB audio interface/audio interface for mobile phone
OverviewIt is possible to connect external audio devices. They can be operated via iDrive. Sound is output over the vehicle speakers. Options for connecting external devices > Connection via US ...

Switching off automatically
System switches off: above approx. 9 mph/ 15 km/h. Switch on the system again if necessary. ...