What happens when it's always below freezing

When you walk in the snow to your car, you naturally get snow on your snowboots. You try to shake most of it off before you get in the car, but some stays on your shoes and then falls on the floor while you're in the car. You also get snow inside your car when you open the door and some falls off the roof or blows in. In Dallas, that snow will melt either when you turn on the heater for a long time or the sun shine in your window for a while or the temperature gets warm again. But here, that snow is still in your car, exactly where you left it, two days later when you get back in your car again. I don't drive far enough for the heater to kick in and make a difference, so I have little snow piles in my car that unless I brush them out or scoop them out, will still be there in two or three more days because it hasn't been over freezing in quite a while.