The cabin Jeffrey lives in was also used in the movies Eraser (1996) and Freitag, der 13. Teil 4 - Das letzte Kapitel (1984).
This is the last film that Howard Zieff directed, because he became increasingly debilitated by Parkinson's disease.
The movie mostly takes place in late April or early May, 1974, based on the inclusion of Nixon's televised address of April 29th, 1974. Ben Stein (who has a small role in this movie) was one of Nixon's lawyers and speechwriters at that time, and possibly even contributed to the speech that is briefly shown in the movie.
Ann Nelson, who played Gramoo in the first film, died several months after its release. Producers were briefly considering getting Estelle Getty to replace her, but ultimately decided to write the character as having died in between both movies since very little of the story took place in Madison, Pennsylvania.