It’s not. It’s designed to be inside as a sun reflector. People just use them to block ice formation too but they won’t last as long that way. They weren’t designed to be rained/snowed on and frozen…but they aren’t expensive so does it really matter?
It’s not. It’s designed to be inside as a sun reflector. People just use them to block ice formation too but they won’t last as long that way. They weren’t designed to be rained/snowed on and frozen…but they aren’t expensive so does it really matter?
I think it stops ice forming by still being inside, by reflecting light and heating up the windshield, but I could be mistaken.