Restoring the factory settings
Press the 
and
buttons
simultaneously for approximately six
seconds until the battery check lamp
flashes twice.
See also:
Cleaning the display
Before cleaning the display, make sure that it is switched off and has
cooled down.
Clean the display surface using a commercially-available microfiber cloth
and TFT/LCD display cleaner.
...
Snow chains
For safety reasons, Mercedes-Benz
recommends that you only use snow chains
which have been specially approved for your
vehicle by Mercedes-Benz, or are of a
corresponding standard of quality.
...
Tire pressure specifications
WARNING
Follow recommended tire inflation pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly, adversely
affect handling and fuel economy, and are
mo ...