The Chez Quis restaurant is the same one used in The Blues Brothers and St. Elmo's Fire.
A deleted scene had Ferris cash a savings bond to pay for the day; it was cut for making him seem a thief, though he has a knot of cash at Chez Quis.
A line about riding the space shuttle was removed after the Challenger exploded.
Broderick and Jennifer Grey got engaged before release, and Ferris's screen parents, Cindy Pickett and Lyman Ward, met on set, married, had two children and divorced.
Ruck's George Peterson voice was an impression of their Biloxi Blues director meant to crack Broderick up.
Broderick's knee injury limited the Twist and Shout choreography, which was by Kenny Ortega of Dirty Dancing and High School Musical.
Ben Stein's lecture was improvised off camera, and the extras laughed so hard that voodoo economics stayed in.
Broderick resisted a sequel, and Hughes's death made it moot.
The 1990 NBC Ferris Bueller show starred Charlie Schlatter with Jennifer Aniston as Jeannie; Parker Lewis Can't Lose is preferred.
The end-credits bus scene was cut from the movie and restored by Hughes, explaining a school bus coming home at 6 o'clock.
Hughes first planned a Mercedes; Modena Design built the Ferrari replicas and, per the hosts, went bankrupt after Ferrari sued, prompting a joke about more blood on Cameron's hands.