After seeing this at several sets of lights in a row, the car driver follows him until he pulls into a parking lot. When they've both come to a stop the truck driver once again jumps out, runs to the back and starts banging on the truck door.
The motorist goes up to him and says, "I don?t mean to be nosey but why do you keep banging on that door?"
To which the truck-driver replies,
Spoiler:
