I have tested 6 different materials as of this post. The results have been lacking. The “Glow” of the decal is hard to see before dusk.
The picture above shows the best material so far. As you can see it has a yellow/green tint to it. The decal doesn’t get much direct sunlight so the charge doesn’t last long. More testing to do!
Monday (Jan 8th), the wife goes back to work so if the sun is shining, the car will be outside all day and I can get a true test.