A number of key moments in the movie were created in the editing room: Jeannie kicking Roonie three times in the face (when there was in fact only one kick filmed); Ferris and Sloane's kiss in front of Roonie was originally just a brief kiss, but was later edited into the long kiss seen on film.
When Ferris picks up Sloan from school, they are standing in front of the entrance to the theater of Glenbrook North High School in Northbrook IL, Hughes' Alma Matter. They then drive the car past the high school's soccer and baseball fields.
Most of the license plates are all abbreviations for titles of films by John Hughes. Katie's = VCTN (National Lampoon's Vacation); Jeannie's = TBC (The Breakfast Club); Tom's = MMOM (Mr. Mom); Rooney's = 4FBDO (Ferris Bueller's Day Off). The exception is Cameron's Ferrari (seen when Ferris first pulls out of the garage), the license plate of which reads NRVOUS.
The 1961 Ferrari GT250 was a modified MG sports car. The producers received several angry letters from car enthusiasts who believed the car shown was a *real* Ferrari and that it was actually wrecked in the film.
The line Ferris says in the bathroom at the French restaurant about Cameron's house being very pretty and very cold was originally supposed to be said by Allison in The Breakfast Club regarding her home life.
"The Car" in the movie was a Ferrari 250GT California Spyder, of which 104 were produced. This version of Ferrari's already famous 250 series was designed specifically for the American market, featuring only two seats, a convertible top, and more horsepower than in its standard European trim.
After the girl in the arcade spits her soda on Ed Rooney, a video game sound effect is heard in the background. Appropriately enough, it's the sound effect that denotes when a player has lost a life in the game Pac-Man.
The yellow and red insignia on Ferris's beret is that of the 32nd armored regiment; the motto at the bottom [illegible in the film] reads "Victory or Death". This was Elvis Presley's regiment when he was in the army and in "G.I. Blues".
Deleted scenes: - Ferris asks his dad on the phone about bonds his father purchased when he was born, he then takes one of them from a shoebox in his father's closet, cashes it at the bank with his girlfriend (telling the hard-of-hearing teller they are pregnant with a jeep), and uses the money to pay for his day off. It was removed because it made Ferris look like a thief rather than a lovable rogue - Ferris orders something in French on the menu, and after everyone at the table tastes it, he is informed by the snooty waiter that he ordered "sweetbreads", which is a French dish made from the thymus gland. It was removed because it showed the waiter getting the better of Ferris, but later in the movie when Ferris is recounting the day to Cameron, he remarks "we ate pancreas".
The bus scene that plays during the ending credits was a scene cut from the movie. It was meant to take place after Jeanie announced that she called the police, and Roonie had to find a place to hide. This explains why the sky isn't dark, and why a bus is taking students home at six o'clock in the evening.
During the parade several of the people seen dancing (including the construction worker and the window washer) originally had nothing to do with the film. They were simply dancing to the music being played and John Hughes found it so humorous that he told the camera operators to record it.
The passage that Ed Rooney quotes when he is trying to console Sloane ("man that is born of woman hath but a short time to live...") is the "First Anthem" for the Burial of the Dead from the Book of Common Prayer produced by the Anglican church. The anthem is based on Job 14:1-2.
The final scene in the garage was shot in early Fall, so each of the leaves on all the trees outside had to be hand-painted green every morning before shooting. In the shot looking up from the wreck at the three friends, the yellow tree with most of its upper leaves gone can be seen reflected in the window.
When Ferris hacks into the school's computer to change the number of absences he had, it is a subtle reference to a scene in WarGames when 'Matthew Broderick' hacks into the school's computer to change his grades.
According to John Hughes in the DVD Commentary (original DVD release), the voice Cameron uses while talking to Rooney pretending to be Slone's father was modeled after a stage director both Alan Ruck and 'Matthew Broderick' had worked for.
The text that appears on the screen when Ferris is explaining how to fake being sick to his parents was added later because John Hughes thought the scene was too flat and not funny enough (according to him in the DVD Commentary).
The song "Danke Schoen" is heard four times in the movie; When Ferris sings it in the shower, when Ed Rooney sings it after ringing the Buellers' doorbell, when Ferris lip syncs the Wayne Newton version during the parade, and when Jeanie sings it while walking down the stairs at the police station.
Early drafts had the Ferris family having younger siblings. When it came time to edit, the final draft actually has evidence that Ferris in fact does have younger siblings, such as drawings on the fridge and a family photo seen in his dad's office.
In 2010, Edie McClurg told Vanity Fair magazine that her character's hairdo should be from the 1960s, "because Grace felt she looked best in the 60s and kept her look from that era." But the women's hairdresser on the set had mainly been hired to blow out Mia Sara's long, straight hair and didn't know how to set the big, dated '60s hairstyles - so McClurg teased, set, and styled her own character's hair. Once McClurg arrived on the set, John Hughes looked at her hairstyle, and the first thing he said was, "How many pencils do you think you can fit in that hair?" They tested it with one pencil, then two and three, but the fourth one fell out--so that was the origin of Grace's first scene in the movie, in which she pulls several lost pencils out of her hair.
In the scene where Sloane is sitting in the taxi with Ferris and Cameron in the floor, Ferris' dad is in a taxi next to them reading the newspaper. As the scene ends you can see the headline 'Community rallies around sick youth,' however wording in the actual article indicate it is an article about a Chicago policeman killing himself.
The name of the Detective that Ferris' mother talks to when picking up Jeanie is Stephen Lim (the name can be seen on door when mother exits office.) This is also the name of the First Assistant Director.
The Cubs game depicted in the movie that Ferris and his friends attend was the actual game played versus the Braves on June 5, 1985, based on research by Larry Granillo published in his Wezen-ball column at baseballprospectus.com on February 6, 2011.
The baseball game that was depicted in the film at Wrigley Field was filmed at an actual Cubs game and took place on June 5, 1985 between the Atlanta Braves and the Chicago Cubs. The Cubs ended up loosing the game 4-2 in 11 innings.
Although one of the key scenes in the film has Ferris, Sloane and Cameron enjoying a Cubs game at Wrigley Field, John Hughes stated on the DVD commentary that he was not a Cubs fan. The scene was set there because of its iconic status and due to the Chicago White Sox rarely playing day games in 1985 during production.
John Hughes personally designed Ferris's bedroom, mirrored mostly on his own bedroom when he was in high school. Hughes said that the room was a disorganized series of pop references and other things because it would represent Ferris's mind.
The idea of a sequel had gone around for years with Ferris in college or on the job somewhere, but the idea was dropped. Matthew Broderick felt that the film didn't need a sequel, that this film was about a specific time and place that we'd all like to revisit and didn't need updating.
During the scene where Rooney fights with the intercom at Ferris' house, there is a shot of the kitchen. On the refrigerator in that shot is a drawing of John Hughes, done by his son who was six at the time.
The Ferrari was originally supposed to smash through the window of the garage and land in the backyard. It over-shot its mark though and hit a fence that was dividing the house from the yard next door.
Polly Noonan who plays the girl that Rooney sits next to on the bus wore glasses that were specially made by the prop department. The lenses distorted her vision so much that they made her nauseous. Also, the glasses were so heavy that she had to hold her head in a certain position to keep them from falling down.
The two men in the funny hats that can be seen when Ferris and his friends are at The Sears Tower were in town on the day of shooting to watch the German Day parade that Ferris goes to later in the film.
After working together on Weird Science, John Hughes offered Bill Paxton the role of the garage attendant. But Paxton turned it down because he felt the role was too small. He admits that he regrets turning it down because Hughes never offered him a role again.
The woman playing the accordion on the parade float was a local woman named Vlasta Krsek. She gained a degree of notoriety from the film even appearing on The Tonight Show Starring Johnny Carson. On the show she played and sang the song Twist and Shout which was one of the songs from that famous scene.
According to the Inside Story documentary, Charlie Sheen's character's name is actually Garth Volbeck. There was going to be a whole back story to his character and family. It was also revealed that the Volbeck's was the family that Ferris's mom was showing the house for sale as her job as a realtor. If you look closely, the tow truck that towed Rooney's car was from the Volbeck's Wrecking Service.
The outfit Ferris is wearing (hat, sunglasses and trench-coat) when he picks up Sloane from school can be seen on a mannequin in his room behind his door as his parents leave his room at the beginning of the movie to go to work.
can be seen in a tiny cameo in one of the early Chicago downtown montage sequences, climbing literally across traffic, from right to left of screen, wearing a light blue jacket and big 'eighties hairdo' (from DVD director's commentary.)
Ferris lip-syncs the Beatles' cover of "Twist and Shout". Ferris quotes John Lennon's song "God" ("I don't believe in Beatles, I just believe in me.") Cameron's Detroit Red Wings jersey references Paul McCartney and Wings, as his Epiphone Texan acoustic guitar (which he played on The Beatles' "Yesterday") sported a Detroit Red Wings sticker from the mid-1970s onward.