Mercedes-Benz S-Class Operator's Manual page 188

Setting the air vents
186
Vehicles without rear-compartment climate
control (only Sedans and vehicles with an
extended wheelbase):
To open/close: press control =.
X
The control pops out.
Turn control = counter-clockwise or
X
clockwise.
To adjust the air direction: hold rear air
X
vent : or ; by the middle fin and move up
or down or to the left or right.
Setting the B-pillar air vent
To open/close: turn thumbwheel ; to the
X
left or right.
To adjust the air direction: hold B-pillar
X
air vent : by the middle fin handle and
move up or down or to the left or right.