Mercedes-Benz 2011 GL-Class Operator's Manual page 190

Driving systems
188
Cornering, going into and coming out of a
bend
The ability of DISTRONIC to detect vehicles
when cornering is limited. Your vehicle may
brake unexpectedly or late.
Vehicles traveling on a different line
DISTRONIC may not detect vehicles traveling
on a different line. The distance to the vehicle
in front will be too short.
Other vehicles changing lane
DISTRONIC has not detected the vehicle
cutting in yet. The distance to this vehicle will
be too short.
Narrow vehicles
DISTRONIC has not yet detected the vehicle
in front on the edge of the road, because of
its narrow width. The distance to the vehicle
in front will be too short.
Obstructions and stationary vehicles
DISTRONIC does not brake for obstructions
or stationary vehicles. If, for example, the
detected vehicle turns a corner and reveals
an obstacle or stationary vehicle, DISTRONIC
will not brake for these.