How to Keep Car Doors from Freezing Shut

Two Methods: Keeping Doors from Freezing Shut, Preventing and Dealing with Frozen Locks
It’s bad enough having to shovel your way through a foot or more of snow to reach your car, without encountering a frozen door frame or lock. If you cannot park your car in a heated garage, your best options are usually an oil for the door frame gaskets, and rubbing alcohol or a heat source of frozen locks.
Method 1 of 2: Keeping Doors from Freezing Shut
1. Replace torn or missing rubber gaskets. The rubber gasket, or seal, along the edge of the car door is the area that freezes, not the metal itself. Inspect the seal on each car door and around each window. Visit an auto parts store to purchase replacements if you notice tears or gaps where water could seep in.
2. Wipe down the door frame. Clean the entire door frame to remove road debris and other detritus that can build up over time. Water can collect around the dirt and freeze the door shut once the temperatures drop.
3. Coat the rubber with a protective liquid. Rub oil or lubricant over the rubber seals with a paper towel. This will repel water, reducing the amount that enters the seal and freezes. There is some disagreement over which oil is best to use, but here are a few options:
A rubber conditioner or rubber care product is probably the safest options for long-term care.
Silicone spray lubricant can last several weeks per application, but it can damage foam rubber seals and should be kept away from paint.
WD40, another light lubricating oil, or even nonstick cooking spray are easily available options, but repeated use can dry out or disintegrate the rubber.
4. Use a car cover. If your car is parked outside, a car cover minimizes the amount of moisture from snow and rain that can reach the door parts and freeze.
Alternatively, find a heavy gauge trash bag and hang it over the open car doorway. Oil the rubber as described above, then shut the door over the plastic.