Besides helping you see better in nasty weather, it helps other vehicles see you. If you want your doors and locks to open, keep them dry. Wash your car to keep salt and other road residues from wrecking your paint, but always dry your car. If you don't, your doors may freeze shut until spring. Check your tires and make sure they are appropriate for winter driving.
Nobody wants to change a tire in the cold.
Your Home Insulate the areas around your doors. Make sure your doors shut completely and no air seeps in around them. Older houses often have doors that swell and stick during the summer months and shrink in the winter. If you feel a breeze as you walk by a closed door, try a bean bag snake along the bottom of the door to keep out the cold air. If air is coming in around the sides or top of your door, call your landlord and ask him or her to better insulate the area.