Theres a little green LED indicator that tells you if its on or off on the mirror.
In the old days...you had a lever at the back of the rear view mirror that you could flick when some inconsiderate tosser was behind you with full beam on.
The autodimming sensor detects the presence of these tossers and darkens the mirror automatically...It also does the wing mirrors as well, if you have the appropriate pack...don't know which one...I bought my car second hand.
Also them wayne kerrs who get the fu%^in stupid Xennon rep's fitted
Edit... That is kleva... I am sure I typed Wan Kers (all one word)
