See also:

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

Maintenance
The battery is maintenance-free, i.e., the electrolyte will last for the life of the battery. Your service center will be glad to advise you on questions regarding the battery. ...

CD/Multimedia
CD/DVD drive Music collection External devices Tone ...