OK, this is for those of you who have access to a service manual or have been to Crossfire training. Does anyone know the theory of operation of the auto-dimming rear view mirror? I'm trying to make some sense of why it does what it does when it does.

I know that it has sensors (I'm assuming photocells) facing forward and aft but for the life of me I can't nail down which conditions will make it dim or not dim. I eventually want to find a way that I can manually dim it if I want to.

Interesting side note: Did you ever notice that because the electrolyte in the mirror has kind of a blue-ish tint it makes it look like everyone behind you has HID headlights?