I was also wondering, if this is not a person in the bed of the truck, could this be a truck used to haul things? I've seen a few pickups that haul racecars with a hitch right behind the window. Usually, its sort of a larger type hitch. I don't usually see them without the trailer though...
Also, if this is presumably a worker, wouldn't there be video of them arriving at the same locations at the same time, but different days? Even if this was someone going in for a morning shift at Burger King, there would probably be some sort of pattern of their daily commute.