Very, very effective.,
Verified Purchase(What is this?)
This review is from: Universal Large Winter Car Windscreen/Windsheild Frost Cover Covers All Your Windscreen
Brilliant and cheap. Because of it's size it covers the whole of the windscreen and prevents frost, even in the coldest of nights. I even use the cover during the summer to keep food cool on the way home from the shops. If used carefully it will not rip or tear.