What if it's snowing while you are driving?
It doesn't collect on the roof and harden while you're driving.
As someone who almost had a serious accident on the highway because of a large sheet of ice that flew off the roof of the car car in front of me and hit my windshield they should do something.
The chunk had probably been there for a couple of days and it was rock hard.
I also saw a woman driving when the entire sheet of ice from her roof slid forward and she could see NOTHING.