I might have some insite on the question.
I recently obtained some little plastic beads that change color when exposed to UV
radiation. The stronger the UV the faster the change and the deeper the color.
When I place them in my car, they change color when the sun comes through the side
windows but not when the light comes through the windshield. I assumed that the
lamination material in the windshield (a plastic) was an absorber of UV where the
side windows are tempered glass and do not have the plastic laminate.
So.... If the suns rays come through the side window, a sunburn is possible.