A theory about bathrooms and icy windshields

I have a theory that may change the lives of working adults throughout the world. Potentially I have made a great discovery.  For years every morning I have walked to my car in the winter not knowing whether I'll have to scrape ice off of my windshield. Although the likelihood increases as the temperature decreases, it is not always the case that low temperatures mean icy windshields. This morning, for instance, it was below 10 degrees outside but there was no ice on my windshield. 

Other mornings it can be 34 degrees out and I have to spend five minutes getting the car so I can see well enough to drive. The fact is that it is not just the cold it is also the humidity that causes this condition. 

I have a theory that you can tell what the status of your car's windows will be when you take a shower. If everything is steamed up after a shower and it is below 35 degrees out you will need your trusty ice scraper. However if you can look at your mirror in the bathroom and there is no steam, you can have an extra cup of coffee because you won't need to scrape any ice off of your car.