In the opening scene set in July 1981, a character plays a tape of The Human League's song "The Things That Dreams Are Made Of". However, this song was not released until October 1981 when it appeared on the band's album "Dare".
Howard and Paul live next door to Lisa in an apartment building. In the opening scenes, Lisa and Paul each come out of their respective apartments into the hallway at the same time, establishing her apartment on the left and the boys' apartment on the right. Later in the movie, after Paul and Howard have gone out to dinner, the same apartments are filmed from the opposite side (through the outside windows), but instead of being mirrored as they should be (with the boys' apartment on the left and Lisa's on the right), Lisa's is still on the left and Howard and Paul's are still on the right.