> I'm amazed that so few people shut the car door first thing after getting in, as I do.

The first thing I do is generally put the keys in the ignition, and the reason I do so, as Howard said, is to free up a hand. I also generally start the ignition then because, hey, I'm already right there; consolidate some steps, I guess. Once my hands are free, then I start doing other fiddly little bits like closing doors and buckling seatbelts and calibrating the sight for the machine guns.