When Lazlo Hollyfeld (Jon Gries) sends in a large number of entries to the Frito-Lay contest, he is mirroring the actions of Caltech students Steve Klein, Dave Novikoff and Barry Megdal, who, in 1974, used a similar strategy to win a McDonald's sweepstakes. Their entries came to roughly 1/5th of the total entries and won them a station wagon, $3,000 cash and $1,500 in food gift certificates.
The "liquid nitrogen" coins have baffled viewers for many years, and are considered by many to be a goof. However, the very first draft of the script shows that it wasn't an error. The thermos contains liquid nitrogen, which in turn contains a column of super-cooled CO2 (dry ice), which is what Chris uses in the vending machine.
In the scene where the military is set up for the laser test fire, the cars in the procession on the dirt road are set up to replicate the JFK assassination.
The film was predominantly inspired and loosely based on actual events at Cal Tech aka the California Institute of Technology in Pasadena, California.
During a crash course in laser technology, the cast and crew received a demonstration of the dye laser as it darted through the colors of the spectrum. Cinematographer Vilmos Zsigmond was troubled. "The naked eye can see the beam coming toward it," he explains. "But it's almost invisible to the camera when it's going away. We went through countless experiments before we learned to 'bounce' the beam and to fill the lab set with smoke, which 'scattered' the light and gave it definition. Otherwise, we would have had a special effect so special, no one would have seen it."