See also:

Activation
The sensors are automatically activated when the reverse gear is engaged. The sound produced by the acoustic alarm becomes louder when the distance between the car and the obstacle decreases. ...

Rear foglights
The warning light on the dial turns on when the rear fog lights are turned on. ...

Spark plugs
The cleanness and soundness of the spark plugs are very important for keeping the engine efficient and polluting emissions down. The appearance of the spark plug, if examined by an expert eyes, is ...