Brake fluid level
If you notice that the brake
fluid level in
the brake fluid reservoir has fallen to the
MIN mark or less, check the brake system
immediately for leaks. Also check the
thickness of the brake linings. Contact a
qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center
immediately.
Do not add brake fluid. This does not
correct the error.
Only check the brake fluid level when the vehicle is stationary and on a level surface.

The brake fluid level is correct if it is between MIN marking 2 and MAX marking 1 on the brake fluid reservoir.
See also:
Vehicle
Activating/deactivating the automatic door locking feature
If you select the Automatic Door Lock: function, the vehicle is centrally locked
above a speed of around 9 mph (15 km/h).
For further ...
Belt height adjustment
You can adjust the seat belt height on the
driver's seat and the front-passenger seat.
Adjust the height so that the upper part of the
seat belt is routed across the center of your
shoulder.
...
Safety
Standard features include antilock brakes, side-impact airbags for the front
seats, side curtain airbags, an electronic stability system and active front
head restraints. ...
