De-icing your car windshield on a cold winter morning can be quicker and easier. Ground crews often use coca-cola to de-ice the By the same token the acid in lemon melts away frost and ice quite effectively. I used to spend so much time warming the car with the window defrosters on, scraping and pouring lukewarm water and scraping more. Now I can be up and running in no time with no scraping. Follow these instructions for a lemon-powered quick start.