WARNING  
If incident light from headlamps is prevented from striking the sensor in the rear-view mirror, for instance, by luggage piled too high in the vehicle, the mirror's automatic antiglare function will not operate.
Incident light could then blind you. This may distract you from the traffic conditions and, as a result, you may cause an accident.

The rear-view mirror and the exterior mirror on the driver's side automatically go into antiglare mode if the ignition is switched on and incident light from headlamps strikes the sensor in the rear-view mirror.

The mirrors do not go into anti-glare mode if reverse gear is engaged or the interior lighting is switched on.