To make your own de-icer, pour rubbing alcohol into a clean, dry spray bottle. Add a few drops of dish soap. Screw the lid on, then invert several times to mix. [2] X Research source
In commercial concentrations, rubbing alcohol has a very low freezing point, so it’s usually OK to leave your de-icer in the car unless you’re expecting temperatures of -20 F (-29 C) or lower.
Be persistent! As far as scrapers go, credit cards can require more effort than dedicated scrapers. You may need to push quite hard to get results. If you’re worried about breaking your card, you may want to double or triple the strength of your scraper by holding two or three cards stacked as you scrape.
Sodium acetate hand-warmers also can be used in this manner and can stay ready in the car. A quick click activates the heat reaction, then you can recharge the warmers by boiling them in water. The advantage of this method over scraping, is because the glass is warmed as you start to drive it will not re-frost. Also, you stay warm and dry inside the car while prepping for departure.
One useful trick for your front windshield is to use your car’s windshield wipers to hold your cover in place. For your other windows, you may want to use small rocks or other weights to pin your cover down.
