NECK-PRO head restraints
The NECK-PRO head restraints increase protection to the driver's and front passenger's head and neck. To this end, the NECK-PRO head restraints on the driver's and front-passenger seats are moved forwards and upwards in the event of a rear-end collision of a certain severity. This provides better head support.
WARNING 
Do not secure any objects (e.g. coat hangers)
on the NECK-PRO head restraints. Otherwise,
the NECK-PRO head restraints may not
function properly, or in the event of a rear-end
collision may not be able offer the level of
protection they are designed to provide.
If the NECK-PRO head restraints have been triggered in an accident, reset the NECK-PRO head restraints on the driver’s and frontpassenger seat. Otherwise, the additional protection will not be available in the event of another rear-end collision. You can recognize when NECK-PRO head restraints have been triggered by the fact that they have moved forwards and can no longer be adjusted.
See also:
Problems with the SmartKey
Problem
Possible causes/consequences and
Solutions
You cannot lock or unlock the vehicle using
the SmartKey.
The SmartKey battery is discharged or nearly discharged.
...
Problems with the rear window
defroster
The rear window defroster has deactivated
itself prematurely or cannot be activated.
- Switch off any consumers that are not
required, e.g. reading lamps or interior
lighting.
When the battery ...
Problems with the seat ventilation
If one or all of the indicator lamps in the seat
ventilation button are flashing, the seat
ventilation has switched off automatically.
The vehicle's electrical system voltage is too
low because ...