Folding back the rear seat backrest
WARNING Risk of accident and injury if the rear bench seat/rear seat and seat backrest are not engaged
Rear bench seat, rear seat and seat backrest can fold forwards.
As a result, the vehicle occupant is pressed against the seat belt. The seat belt cannot perform its intended protective function and could cause additional injuries.
Objects or loads in the boot cannot be restrained by the seat backrest.
Make sure that the rear bench seat, the rear seat and the seat backrest are engaged before every trip.
NOTE Damage caused by trapping the seat belt when folding back the seat backrest
The seat belt could become trapped and thus be damaged when the seat backrest is folded back.
Make sure that the seat belt is not trapped when folding back the seat backrest.
Vehicles without a memory function: move the driver's or front passenger seat forwards, if necessary.
Vehicles with a memory function: if at least one part of the seat backrest in the rear is folded back, the corresponding front seat will automatically return to the most recent original position.
Fold the corresponding seat backrest 
back until it engages.
back until it engages. If the seat backrest is not engaged and locked, this will be shown on the multifunction display on the instrument cluster.