Continuity mistake: When Fry and the kid are racing along the motorway, just after they let go of the cars they are holding onto, they head into a lamp post. This leads them to banging their heads and collapsing on the floor, because the ribbon they were holding onto forces them into the lamp post. When they fall on the floor, the dust shoots up. After the dust disappears, the lamp post has as well, meaning that the ribbon isn't actually tied around anything.