See also:

Setting the temperature in the rear compartment using the front control panel
Turn the SmartKey to position 2 in the ignition lock. Activate the rear compartment function via COMAND. The rear-compartment climate control can be controlled via the front control panel ...

Additives
Do not use any additives in the engine oil. This could damage the engine. ...

SmartKey
0. To remove the SmartKey (shift the transmission to position P) 1. Power supply for some consumers, such as the windshield wipers 2. Ignition (power supply for all consumers) and driv ...