See also:

Snow chains
For safety reasons, Mercedes-Benz recommends that you only use snow chains that have been specially approved for your vehicle by Mercedes-Benz, or are of a corresponding standard of quality. ...

Problems with the SmartKey
Problem Possible causes/consequences and  Solutions You cannot lock or unlock the vehicle using the SmartKey. The SmartKey battery is discharged or nearly discharged ...

General notes
You can store music files in MP3 or WMA format in the MUSIC REGISTER. The memory has a capacity of approximately 7 GB. Retain the original music files in a secure location. An error in COMAND ...