See also:

Checking the coolant level
1. Do not open the hood until the engine has cooled down. 2. Turn the expansion tank cap counterclockwise slightly to allow any accumulated pressure to escape; then continue turning to open. ...

The concept
The system is functional at speeds beginning at approx. 20 mph/30 km/h. It maintains the speed that was set using the control elements on the steering wheel. The system brakes on downhill gradie ...

Closing the windows and glass sunroof/panoramic glass sunroof
Driving with the glass sunroof/panoramic glass sunroof and windows open results in increased air resistance and raises fuel consumption. ...