Been thinking about this for sometime now.
my problem- is where to find something that is wide enought to cover the complete plate.
my thoughts- http://www.drillspot.com/pimages/2130/213045_300.jpg
if you look at the helmet.. my idea would be to use one that is battery powered. so that way you can solder in dc voltage(with voltsage reg to control and give correct volts to panel) from the car to power it.
second in regards to the solar panel. well we all know its job is to dims the glass. so instead of having it work like that my idea would be to bypass the solar panel and have it work on a switch. so we can control when it when to go dark.
love to get some feedback from ya