DIY Windshield De-icer: Clean, empty spray bottle + 2 cups rubbing alcohol + 1 cup water Fill the bottle with 2 parts rubbing alcohol, and 1 part water. Spray rubbing alcohol solution on the ice and it will melt instantly. I may need this tomorrow.
Never use hot water to de-ice car windows (doing so could crack them). Instead, smack your hand on the hood and trunk to break up sheets of ice, and (as long as the exhaust pipe and radiator grill are clear) start the car and turn on the heater and headlights. Or, keep a small spray bottle filled with 1/3 water and 2/3 rubbing alcohol in your car, and spray directly on your windshield to melt ice in seconds.