Frost on Inside of Car

Nothing is more annoying than getting frost on the inside of your car windows. In the cold, it's normal to get frost on the outside of the windows. It's not normal to get it on the inside. It happens to my car all of the time. It's impossible to get off. You can't scrape it off because it doesn't work very well at the awkward angle you are trying to get it off in. When you put the defroster on, it gets the ice off from the outside only. Once it gets warmer out during the day, I can see the frost from the inside of my back window melting. It turns into water inside my car. I take a towel and dry it off. I have no idea how to prevent frost from happening on the inside. Good thing the low temperature won't be -9° later this week. Oh wait... Have I mentioned I can't wait to move to North Carolina?