The entire October 1982 edition of National Lampoon magazine was devoted to O.C and Stiggs, it being called "The Utterly Monstrous Mind-Roasting Summer of O.C. and Stiggs". The movie was made around a couple years after this issue was first published.
Some movie posters for this film featured a text preamble that read: "These two friends have one last chance to turn this summer into the most mind-roasting, incredible time you've ever had. O.C. AND STIGGS. Adventures in upper middle class suburbia".
When the helicopter lands in Schawb's yard, Goon's arm can be seen hiding behind the seats. The pilot just leans over so that Goon can jump out from behind and look as if he was the pilot.
Oliver Cromwell 'O.C.' Ogilvie: [talking about the car dealer, Ms. Bunny]
It was the last case that gramps had before he retired... she got off with a hung jury.