Swank4

I just bought a new pair of eyeglasses and they have the "Transitions" feature = exposure to UV light causes them to darken. I left these glasses on my dash and they changed color slightly and it was only a cloudy day...meaning that UV still penetrates the window (I thought a thick piece of glass like the windshield would block all of the UV). I thought you only needed them in intense sunlight and mostly to prevent high heat buildup but I now know that UV is always an issue. I keep a window screen on the front windshield whenever parking the car outside now. Don't want my dash to fade/crack over time!

curbside crackdealer

I use it even when I park in a garage. With the tint, makes it difficult for people to peek inside

StoneMan

I keep mine in the trunk all year round! FWIW, I doubt our dashes would suffer as badly as domestics

Oo.et.oO

glass doesn't block "any" UV except at extreme angles.