In the first scene, before the Creeper appears, Jack Taggart Jr. is working underneath a truck. The device he uses to slide underneath it is commonly referred to as a "creeper".
Just after the opening sequence when the team is singing on the bus the camera moves from the front to the back of the bus with a clear view out the back window. It looks off for 2 seconds at one of the characters and then you hear the horn of a truck with a giant cockroach on the roof on it behind the bus. When the camera was moving from the front to the back of the bus there was clearly no truck approaching the back of the bus.
The sun really bounces around in the first scene. Although the Creeper is seen flying off into the setting sun (and yet, the sun is at the backs of the people chasing it) the sun is high in the sky moments earlier when the boy looks up at the Creeper on the scarecrow post.