14. The Jennifer Switcheroo
Few audience members will notice that the actor who played Marty’s girlfriend, Jennifer, changed from the first film to the second. In the first movie, Claudia Wells played the part. Family obligations kept her from reprising the role, so Elisabeth Shue played Jennifer in parts two and three. In one shot in part two, they repeat a frame from the first film, but with the new actress in the shot. Fans note that, in addition to a different actress, the house in the background changed from peach to yellow. The role of Jennifer was so small in the first film that most never noticed.