Logic Riddles

Question: When is a car not a car?

Question: Why don't honest people need beds?

Question: What is in the middle of nowhere?

Question: There were 2 trains heading the opposite directions on the same track.1 was going North, and one was going south, There was a 100m gap between them, avoiding the collision, 2 men saved the trains from colliding on time, Who were they and how did they save them?

Question: What goes on and on and has an 'i' in the middle?