Near the end of the first film, when Marty finally gets back to his time and races off to try and save Doc from his gruesome fate, a homeless man Marty refers to as “Red” yells at him, complaining about drunk drivers.
The mayor of Hill Valley back in 1955 was also named Red, and while many think this was intentional, Michael J. Fox, Marty’s actor, made the line up on the spot. While it’s certainly in-tune with the rest of the movie, the filmmakers have neither confirmed nor denied if the characters are one and the same.
Not by the Band
When Marty scares his father into asking Lorraine to the dance, he does so with a crazy alien getup and some shocking music by “Edward Van Halen.” The band you're thinking of is “Van Halen,” but why was the “Edward” squeezed in there at the top?
It's because while Eddie himself (R.I.P.) was okay with his name being in the movie, the rest of the band wasn't. So, Eddie whipped up a quick solo for the film, and the prop guys added his first name to the tape, to ensure that no copyright violations were taking place.
More Than Just Johnny
One of the most memorable parts of the first movie was when Marty is conscripted into the band at the high school dance. He plays Johnny B. Goode, one of the most famous rock and roll songs ever – since it was one of the first.
Marvin Berry calls his cousin Chuck to tell him about the sound, a reference to Chuck Berry, the song's actual creator. However, Marty also references other famous guitar players like Pete Townshend from The Who kicking over the amplifier, Angus Young from AC/DC lying on his back while playing, and Jimi Hendrix playing behind his head.
Almost Didn't Get Made
It wasn't a smooth ride for this famous film, and though the movies are now pretty much universally-loved, the pitch for the movie was rejected a staggering forty times before Universal finally purchased it.
One of the main reasons it was rejected was because of the incest detail. Disney in particular brought up the fact that they didn't like Marty being kissed by his own mother in a romantic way, though Lorraine was unaware of the relation, and immediately after kissing him she is creeped out in a manner she doesn't fully understand.
How Many Pines?
The changes wrought through time by Marty's antics are one of the big problems the movie presents as drama – if his father and mother don't get together, he will vanish. But there's more.
At the beginning of the film, Doc Brown and Marty experiment with the DeLorean at Twin Pines Mall. When Marty goes back in time, he crashes through one of two pines at the edge of the farming property, and then all the way at the end of the film the name of the mall has been changed to Lone Pine Mall. It's hard to catch if you aren't paying attention, but an incredible detail nonetheless.