See also:

Air distribution table
...

Lower cross member
The front structure has been supplemented by a lower cross member that adapts the front to the height of a normal-sized passenger car. This enables the other car's deformation zones to function as ...

Activation
PAC is activated when the gear selector is moved to R if the system is selected in the MY CAR menu system or by pressing the CAM button in the center console. See page 133 for a description ...