Actually, the producers of the film wanted Fox first, but didn't anticipate the unexpected break in the shooting of his hit TV show "Family Ties" schedule. When the break did come, they halted shooting with Stoltz and went back to their original choice of Fox. It was a scheduling conflict that originally allowed Stoltz to star but an unexpected break in shooting that allowed Fox to appear in the movie.
Crispin Glover did not appear in either of the sequels due to a breakdown in contract negotiations, and this is why the storyline about him being shot in the alternate 1985 was written into the second movie. It was required, however, that his character appeared on the second film because Marty goes back to 1955 again, so the producers used what footage they could from the first film and used a stand-in with a fake nose (!) to shoot scenes they couldn't build up from archive footage. I have heard that Crispin Glover attempted to sue them for using the archive footage but I don't know whether this is true or if it is, what the outcome was.
The DeLorean cars were built in Dunmurry, a short distance south of the city of Belfast in Northern Ireland. Only 8,583 DeLoreans were manufactured in 1981, 1982, and 1983: 6,539, 1,126, and 918, respectively. Of those, about 6,000 are believed to be in circulation - a few hundred of them outside the United States.
The character name of Emmett (Doc's name) comes from the word "time", spelled backwards and pronounced as syllables (em-it). Doc Brown's middle initial is "L" but no name was ever actually given. Bob Gale, the film's writer, was asked about this and gave him the name "Lathrop" (almost "portal" backwards - see above)
There was a scene that was cut from the movie during which George McFly (being the pushover that he is) buys an entire case of peanut brittle from a little girl who was selling it door-to-door. The payoff for that scene is when George is eating peanut brittle for dinner.
Every scene that was shot at the "Twin Pines Mall" had to be shot after Christmas and late at night due to the fact that there were twice as many shoppers, and the mall was decorated with Christmas lights.
A "Black Pride" organization were upset with the creators of BTTF. They claimed that it was wrong to suggest that Marty, a white man, invented rock 'n' roll by playing Chuck Berry's (a black man) Johnny B. Goode before it was even released.
The first voice you hear in BTTF, (the man on the radio talking while the pan of all the radios is being shown) is also the voice of the major toy, Furby and the original voice of Goofy. His name is Tony Pope.
The first idea for time traveling was not by lightning, but by a nuclear explosion. The first script had them go to a nuclear site to be able to time travel. Bob Gale and Robert Zemeckis decided that would be too expensive and chose lightning instead.
Michael J Fox is really not playing or singing Johnny Be Good. The music and singing were both pre-recorded. Michael did have to learn the song note for note to make it look like he was playing it. At the end of the film, his character Marty McFly gets credits for singing the song.
Originally, the studio boss wanted to make certain changes (Professor Brown --> Doc Brown, Chimp -> dog (no movie with a chimp makes a profit), Marty's mom's name from Meg to something else, (incidently Lorainne is his wife's name) including the title of the movie. He was the only one who didn't like the title, "Back to the Future" but the makers stuck to their guns. The alternate title, was "Spaceman from Pluto". The studio boss sent a memo outlining changes to the script for the new title and they didn't know what to do as he was the BIG BOSS of the company. In the end Stephen Spielberg sent a reply saying (paraphrase), "Dear Sid, thank you so much for your most humorous memo, we really all got a good laugh out of it!" So the name stuck as Spielberg knew he would be too proud to admit that he had been deadly serious!
Marty got a four wheel drive Toyota pick-up truck at the end of the movie. At first it was planned to be a Toyota Supra sports car, but replaced with the pick-up truck because of the changing trends of american car buyers.
With Eric Stoltz they shot most of the movie for 6 weeks before he was replaced by Michael J Fox. I actually heard the real story from the script supervisor on the Film, in 1989 when I worked with her on a TV movie. She explained how in dailies for the first week, Spielberg commented "oh that's an interesting way he's playing it." Which was a more quiet, understated and serious Marty Mcfly.
It was 1984 and Stoltz had just been nominated for his role in "Mask" and was being a method Actor on the set of Back To The Future, to the point that the cast and crew could only address him as Marty. He had his parking space and dressing room Labeled "Marty Mcfly". Which he had 2 rooms, one for Eric and one for "Marty". If people would say "hey Eric" he wouldn't respond and quickly it became evident the performance was lacking the humor Zemeckis wanted. This script supervisor said by the 3rd week people were just yawning through the dailies. Also the set was just really tense all the time because of Eric. This affected much of his early career.
She said Spielberg, by week 6, went to Eric on the set, because the Producers had made a decision, and Spielberg said "Eric I have to talk to you" and Eric replied "I'm not Eric. I'm Marty" and Spielberg allegedly said "No, you're Eric and you're fired".
-Although the exact wording may have been slightly different in real life, this is how she recalled their interaction.
Eric apparently got his stuff from the dressing room, slamming doors. Then peeled out in his car as he drove away. She said when Michael J Fox came on they basically started the movie over and everyone was so much happier and relieved.
In the novelization of the film, the story begins with Marty in class listening to music as they watch a documentary on the A-bomb. He is called out of class to take a phone-call which turns out to be the phone call from Doc Brown asking him to meet him at the mall.
This was also in an early version of the shooting script on which the novel was based.
In an early version of the Back to the Future screenplay, instead of doc having a pet dog named Einstein, doc has a pet monkey named Shemp. Also in the screenplay Marty's girlfriend is Suzy Parker and not Jennifer Parker.
One scene that was originally in the movie showed Marty, in 1955, at the high school that his parents attend, and he looks into a classroom and sees his mom cheating on an exam. This is interesting because she, in 1985, is preaching good habits to her children. This scene was filmed to portray that Lorraine wasn't exactly an angel in her teen years, but eventually removed from the movie.