I have to make this point, for the last time. The riddle about the "car" had only one RIGHT answer! Sure alot of other things could have happend but it didnt!
That type of riddle is very common, they are called "yes/no riddles or yes/no mysteries. In that you get the riddle and then the others get to ask questions that can be answer with yes or no! This goes on till someone gets the right and only right answer!
Another example would be... You find a man's dead body in the desert , there are no tracks leading to or from his body! He has on regular type clothes and has a pack on his back, how did he die?? ( the right and only right answer is that he died when his parachute didnt open and he hit the ground!) Sure he could have died of exposure and then a sand storm came up and hide his tracks, or some other stupid , way out there far fetched idea. But those answers would be wrong!