Revealing mistake: While Wayne, Diane, Patty, and Gordon are in the laundry basket, Adam and Mitch carry that basket upstairs. When Mitch says, "I bet my parents wish I didn't have a medical problem," the camera turns to follow the boys as they walk up the stairs, and the left wall (with striped wallpaper) of the staircase is missing to accommodate the camera filming from that angle. It's visible again when Mitch says, "And I feel fine." (00:35:35)
Revealing mistake: When the boys take the laundry basket upstairs, there's a shot from in front, and one can see none of the four family members is inside. The filmmakers didn't even bother to place toy figures inside.
Revealing mistake: After the toy car crashes, the group falls down a hole, but their clothes don't react to gravity, revealing the green screen trick.
Revealing mistake: When the group is riding the toy car, in the wide shots of a real toy car, they disappear.
Revealing mistake: While Patti and Diane talk next to the spider, in the close-up shot, the web becomes a thick white rope that has nothing to do with what we see in the wide angles.
Answer: Epoxy resin is sometimes sold in two seperate tubes. You have to mix the contents of both for the epoxy to harden into plastic. It also shows how weird he is, as epoxy tends to smell pretty foul.
Grumpy Scot