I think they used to have this stuff on the glass bathroom toilet stalls at a nightclub in Dallas. When you latch the door, the glass walls go opaque.

 

But imagine being pulled over for tint, than acting a fool - "What Tint Officer?"

 

You would have crashed into the cop because you wouldn't have seen anything because of this "tint".

 

Ya this material is basically unusable while driving and is very expensive. It also does not look like traditional dark tint like others have said but kinda white.

Still kind of cool but a limo tint or scalable electro 5/15/30 tint needs to be invented

 

No, thats Smart glass. It like frosts the glass when you run electricity through it.