That woman is insane, she's reached Martha Stewart levels of obsessive. Let's look at this practically.
Objective
Keep ice and snow off your windshield. A quick trip to work.
Order Of Battle
One piece cardboard
ulfa knife
Strategy For Offence
Cut cardboard to shape, place on windshield.
The Opposing Forces - Mother Nature
Order Of Battle
Wind, rain, sleet, snow.
Strategy For Defence
- Access to cardboard (Supply/Logistics)
Are you KC Scott or IndyFrisco? Are you buying big ticket items (fridges/flatscreen TVs) every week? If not, how much time are you spending acquiring cardboard? How does this weigh against time spent scraping? Are you re-using the same piece of cardboard over and over again? Where are you storing this mouldy piece of cardboard when not in use?
- Wind
Cardboard and newspaper are lightweight, most storms are accompanied by wind. Your protection will be down the street, being conservative, 50% of the time.
- Cardboard has no memory
After you cut your cardboard to fit and place it on your windshield, How will it stay tight on the perimeter? Odds are, there will be a gap at the top of the vehicle, allowing ice and snow to penetrate behind your lines and collapse your front.
- Rain
As mentioned before, if the cardboard gets wet before it freezes, you're fucked.
- Social Contract
While I hate my neighbours and wish they'd die in an artillery barrage, I am under some contract not to cover my vehicle like a gypsy wagon. It's OK not to be the best on the street, just don't be the worst.
I admire your innovative thinking, but I'm not sold.