Save time in the mornings, and save the gas you idle away while scraping your windows. I read this tip in my dollar saving newsletter. I hope it works.

To prevent your car's windows/mirrors from icing up in the
winter, treat the windows before you go to bed each night. The
window treatment can be made up of 3 parts vinegar to 1 part
water and placed in a spray bottle. This mixture will prevent
ice from forming. It is important to spray all of the car's
windows and not just the windshield. You can also use the same
mixture replacing the vinegar with rubbing alcohol.