See also:

Removing the towing eye
  Loosen the towing eye and unscrew it.   Attach cover 1 to the bumper and press until it engages.   Place the towing eye in the vehicle tool kit. ...

4MATIC (permanent four-wheel drive)
4MATIC ensures that all four wheels are permanently driven. Together with ESP® and ETS, it improves the traction of your vehicle whenever a drive wheel spins due to insufficient grip. WARNIN ...

Important safety notes
See the "Important safety notes" section If ESP® detects that the vehicle is deviating from the direction desired by the driver, one or more wheels are braked to stabilize the vehicle ...