Sounds interesting but can you make the glass sensitive enough to pick up headlights and distingush between things like street lights and traffic signals.

I think that is very possible, but does that out weight the effects of having "visibly" tinted glass for a period of 3-5 seconds while driving? I think the glass tinting itself would be the hazard then. I have driven cars with moderate tinting on the windows at night, and it is definatly harder to see out of. So much so that sometimes I am forced to roll the windows down just to make sure there isnt a vehicle with dim headlights that i cannot see, bc of the tint. Overall i like the idea tho, but will it be effective?

Aren't tinted windshields illegal? Check your motor authority.

Getting the glass to tint against headlights at night and sunlight would be a real challenge. That's at least a 1000x change in magnitude. The problem seems more to be that suspect headlights are pointing more ahead than downward, or perhaps that too much light is leaking/straying from the intended path.