Visible crew/equipment: At the beginning of the movie when Clark is entering his house and the camera angle is from inside, just as he opens the door there is something red on his front porch. If you look at any of the previous scenes, that red thing isn't there. It's the bottom of a sunscreen being used to block the bright sunlight (which would have flooded the camera) behind Clark as he enters the house. (00:01:44)
Visible crew/equipment: The camera and the cameraman are reflected in the chrome of the Griswold limousine when they are driving down the strip.
Visible crew/equipment: When Clark asks for Audrey and Russ at the door, there's a production member reflected in the mirror behind Clark, right before he walks in front of the television to watch the commercials.
Visible crew/equipment: In the scene where Audrey is dancing on the sign with her cousin, you can see the safety cord in the shadow when she is at the top.
Visible crew/equipment: In the beginning of the movie after Clark trips over the bicycle in his driveway and approaches his house you can see the microphone in the upper middle of the screen momentarily.
Visible crew/equipment: Right at the start, when Clark is stepping up to the front door, you can see a microphone appear down from the top of the screen. Playing this scene in real time is the best way of seeing it, but watch closely because it's only in view for about a second. (00:01:38)
Visible crew/equipment: When Christie Brinkley is keeping pace with Clark in her sports car, the camera vehicle is reflected in the passenger side window of her car. It's not the Griswold's minivan.
Answer: The sign said $30,000.