Okay, in the episode where the kids are at the amusement park and the evil clown thing is chasing them, watch the part where Scooby and Shaggy get away by riding Monster Mountain. At the end of the ride, Shaggy and Scooby are in car number three. Then, the camera moves away from them and over to the clown. Then it moves back to Shaggy and Scooby, who are now in car number one. Whoops!