How can I tell whether the windshield and side windows of a car are UV protecting?
I know I could use a portable UV radiometer/sensor, assuming I can place the car under the sun. What are other solutions?
Use a UV ray light. Keep phosphorus material inside see if it lights up.
Light on the outside, glowing material inside, through the window you hope it does not light up.
According to this website there are two different types of UV radiation, UVA (longwave) and UVB (shortwave). Glass in and of itself absorbs the UVB light. The front windshield is treated to absorb UVA light as well. The sides and back window are not treated to absorb UVA light and will allow it to pass through. Unless UVA absorbing tint has been applied to your side/rear windows, the light will pass through.