So I noted while driving the other night that only the internal rear view mirror and drivers mirror dip (get darker) automatically. The passenger mirror doesn't.

Cost cutting? It seems to me I'm still as likely to be blinded by traffic behind me from the passenger side mirror as I am from the drivers and rear view mirrors?

 

Correct, the passenger mirror is not dimmable .


Be careful with the drivers side glass as it cost around €500

 

Benz has always done this. Normal as Vic says.