See also:

Trailer towing
PARKTRONIC is deactivated for the rear area when you establish an electrical connection between your vehicle and a trailer. Fold in the ball coupling if the trailer tow hitch is not required. ...

De-registering (de-authorizing) a mobile phone
Mercedes-Benz USA, LLC recommends deauthorizating in both COMAND and the mobile phone. Subsequent authorization may otherwise fail. To call up the telephone menu: press the function button ...

Activating RACE START
Depress the brake pedal with your left foot, and keep it depressed. Turn the drive program selector clockwise until the RS lamp lights up. The multifunction display shows the RACE START Conf ...