Windows fogged up on the inside
Activate the cooling with air
dehumidification function 
.
Activate automatic mode
.
If the windows continue to fog up,
activate the defrosting function.
You should only select this
setting until
the windshield is clear again.
See also:
Adaptive Highbeam Assist
You can use this function to set the
headlamps to change between low beam and
high beam automatically. The system
recognizes vehicles with their lights on, either
approaching from the opposite ...
Vehicle data, GL 550
The data stated here refers specifically to a
vehicle with standard equipment. Consult an
authorized Mercedes-Benz Center for the
data for all vehicle variants and trim levels.
...
Important safety notes
It is particularly important to use a safety net
if the vehicle is loaded with small objects
above the level of the backrests. For safety
reasons, always use a cargo net when
transporting load ...