The size of the lipstick word "geek" on Sam's locker changes several times.
(at around 8 mins) The camera angle changes for a few seconds to show Lindsay's view as she walks through the hallway, the same extra can be seen walking towards Lindsay as can be seen walking behind her both before and after the point of view shot.
Fruit Roll-Ups is a brand of fruit snack that debuted in grocery stores across the United States in 1983 yet they appear on the show set three years earlier in 1980 before they were available for sale.
When Kim and Lindsay are driving around, mountains (which do not exist in suburban Detroit) can briefly be seen in the background.
Kim's mom refers to Benton Harbor as being "up there" when in fact it is West of Detroit.