Now that the winter weather is upon many of us, I was wondering if anybody has a trick to prevent windshield from freezing in the mornings. Leaving the car idling to defrost is not an option. It takes a while for the car to warm up and start defrosting the windshield. Forester is particularly notorious for this and my wife's drive is a little over a mile. The car doesn't even reach to the operating temperature.

In the past, I used 50% rubbing alcohol (IPA) and it works wonderfully but I noticed that the paint on the top of the windshield has started bubbling. Not too sure if its because of the IPA. I have used Prestone deicer as well, that also works well but it gets expensive over the period of time. I have -30F windshield washer fluid but it doesn't cut it. So thought if there is anything that I can layer windshield with to prevent morning freeze yet not affect the visibility.

I have tried using windshield cover unsuccessfully.

Thanks for any ideas.