See also:

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. ...

Treble, bass, balance, and fader
▷ "Treble": treble adjustment. ▷ "Bass": depth adjustment. ▷ "Balance": left/right volume distribution. ▷ "Fader": front/rear volume ...

Enabling DVD system
The DVD system can be enabled via iDrive. 1. "Settings" 2. "Allow rear control" 3. "Rear DVD system active" Rear DVD system active ...