Also according to Busey and Director Steve Rash, the scene at the roller rink after the band's first rock number in which the extras clapped and cheered was an unexpected reaction to their performance. As you can see in the film, Busey, Smith, and Stroud sort of lose their place and start nervously laughing.
In the scene where Cindy Lou gets on the bus to go back to college, Busey was originally supposed to answer her question of "What am I gonna tell the kids at college?" with "Cindy Lou?...Kiss my ass!" But director Steve Rash didn't like that line and so they came up with "Boola, Boola." instead. (According to DVD commentary)
Madman Mancuso, played by comedian/impressionist 'Fred Travelana', is based on a true story about DJ Hall-0f-Famer Dick Biondi. Travlena even managed to look and sound like the real Biondi.
The closing caption refers to "Clearlake" (one word), Iowa. The city is "Clear Lake" (two words), as seen at the city's official website, http://www.clearlakeiowa.com/. The same mistake is made in the name of the (erroneous) "Clearlake Auditorium".