It is possible to set whether automatic starting of the heated rear window and door mirrors should be activated/deactivated when the driver is in the car.1 With automatic starting activated, electric heating will start when there is a risk of ice or mist on the window. The heating switches off automatically when the windscreen/window is sufficiently warm and the ice or misting is gone.
Open the climate view in the centre display by tapping on the temperature button at the bottom centre of the centre display.
Press 
Select the desired setting under Auto rear defroster to activate/deactivate automatic start of heated rear window and door mirrors.