I do whack on all the heated options when in the car; windscreen, back, side mirrors and seats. But the windscreen takes some time with heavy frost. Used to use a de-icer spray, but let's just say that I punctured the can once and looked like a dick. Bought a plastic ice scraper from Halfords which was ok but by the time your done you have frostbite
yes I know ice is cold. Probably doesn't help that I give myself about 20 minutes to rush to work. I'm thinking speed and efficiency....blowtorch...boom