GUEST,Lighter

Lighter--

You said, "A second contestant, facing two doors, has a different situation." There is no second contestant in the Hall Game. There is only the contestant and Monty. There is a new contestant playing the exact same game (except perhaps for the location of the car) on the next show; his outcome is independent of what you did. But he and you should chose a switching strategy to maximize the chance of getting a car.