Yeah but......there's some major downsides to some of these "tricks". First, the onion trick will work to about 15 degrees- then it doesn't. It also leaves a nasty film that makes it difficult to drive at night, due to the glare. True- rubbing alcohol will lower the freezing temp of your wipers, but will make them deteriorate 3 times faster. And lastly, never heat a new car key with an open flame. Most late model keys have a built in sensor for anti-theft & anti lock-in. You melt that sensor, your car won't start and you're at the dealer spending $150.00 for a new key.
I use a Frost Guard cover over the windshield and it works great. I also use a yoga mat over the door so that I can open it if the temp was at or below freezing the night before.