Have a look at our EL inverters and see if any of them might be suitable. From a quick look, it seems that EL panels operate on a similar principle to your film. Here’s some more info on how EL inverters work. I have never personally used electrochromic glass before, so I’m not sure if this will work, but at least it’s a starting point.
Putting this in a car is a very interesting concept, I’d love to see how you get on with it!