Here's a nice tidbit I just found out about: Formula-1 cars are so light and fast that they can defeat gravity simply by the force of the friction they can create against the ground. This means that a Formula-1 car could easily race top-down, on the roof of a tunnel, if one was built properly to let the car slide to the side first and then eventually race on the roof. I guess that those videogames that let you do that didn't have it so wrong after all.