I saw those films too. The car circled the block a couple times before stopping and the woman grabbed the package. I guess people like that were driving around to find holiday packages that were being delivered.
I tend to think it is the kids in the neighborhood. I live in a small circle and there are few houses with kids and I would hate to think it is one of them that I actually know. There are kids from other streets who play with the ones next door quite a lot though.
I need to talk to them, and their kids, about who might be doing it.