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. The vehicle automatically adjusts the volume of the microphone on the telephon ...

After the ignition is switched off
The roof can still be operated for approx. 1 minute, as long as no door has been opened. ...

Long-term vehicle storage
Your service center can advise you on what to consider when storing the vehicle for longer than three months. ...