I wont use De-Icer on my car, It will strip off any wax if it comes in contact with the paintwork.
Due to the high acidity of chemicals used in De-Icer the only real way to get around it is to thoroughly rinse off any remaining product left on the paintwork but this is easier said than done.
I avoid using Plastic Ice Scrapers too as these can easily cause scratches on the Glass or Plastic Headlamps, Although a Rubber Squeegee type is ideal for removing any partially De-Frosted Ice or Frost rather than using the Wipers on the car.
I usually use cold Water and keep a 2L bottle of Water in the car at all time, Pour it on the screen with the car running and wait a few moments. Does the job and is harmless.
Interesting thread on DW about defrosting Do's and Dont's...
I would like to say common sense dictates to avoid using boiling water; however, some people are daft enough to pour this straight onto a frozen window. So I would like to take the opportunity to advise you not to use boiling water to defrost a car window
Cold water straight from the tap is sufficient for de-icing your car windows. So much so, that this is all I have used for years. You may be wondering why cold water and not luke warm water? Well the answer is simple, hot water freezes quicker than cold water due to the Mpmeba effect. What you also need to think is that any water is warmer than ice, so it’ll be enough to melt the frozen ice (water) on your car.
After rinsing your windows and lights with water, use the squeegee on your ice scraper to remove any standing water (or your wipers for the windscreen). This will prevent any possible re-freezing of any water left on the windows.
