According to Tommy Chong and various sources, this movie made more money on a second-run on double-bill with The Blues Brothers (1980) than it did on its first release. Interestingly, Paul Reubens appears in both films.
On the wall where the phone is in their house is some graffiti "Dave's not here" a reference to one of their earlier audio sketches
In the scene where Red steals a Ferrari from the Comedy Store, the license plate on the car is OU812, which Van Halen used for their album of the same name.
Cheech's boss' name - Stromberg - is a reference to the "Up His Nose" skit, from their 1973 album 'Los Cochinos.'
Dan Aykroyd and John Belushi were filming The Blues Brothers (1980) on the same lot and visited the Burbank set of 'Next Movie', still in their Blues Brothers costumes, where Dan ended up directing the sequence where Chong urinates from out of his window. Chong observed in the footage Aykroyd shot that you could see the water hose being pulled out of frame, but Aykroyd told him to keep it in, because the audience would think it was Chong's penis.