Don't get stuck out in the freezing cold with frozen car door seals.
This made me laugh when I nipped out to ASDA last night, about 10/15 members of staff trying to get into there cars but couldn't because the door seals were frozen shut.
I thought everybody new about using vaseline or silicon spay on the seals to stop them freezing shut.
I'm lead to believe that using a petroleum pased product would degraded the door seal, maybe in old rubber compounds but not in new types.
I've used vaseline for many years on the doors seals of different types of cars this no visible effects, all it takes is a very, very light application round the seals to the point that it only darkens the rubber.
Silicon in the form of a stick or spay seems to the most recommened product to use and is available from most supermarkets and autofactors.
Its also in interior back to black spay and other type of dashboard shine sprays.
Hope this helps, please add if you know other methods.