Executive Meddling: Disney and Warner Brothers only allowed the use of their iconic characters if they got exactly the same amount of screen time, hence the "Donald Duck/Daffy Duck" duel, and the "Mickey Mouse/Bugs Bunny" scene. The two Ducks' piano duel ends in a draw, with it being unclear who even started the fight, and Bugs and Mickey both try to dissuade Eddie from taking the spare because it's not a spare parachute but a spare tire. Tropes Are Not Bad; these scenes were some of the funniest in the movie.
It also works out better that way because this is exactly what people wanted to see, It's not enough to just have them in the same movie, you want to seem them actually interacting with one another.
There were also some individual, quick sequences with one character, such as Dumbo, Yosemite Sam, and Tweety. The length of these scenes were probably under a lot of scrutiny as well in order to not show favoritism towards one company.
A persistent rumour also claims that the reason the film's title has no question mark at the end of what is presumably a question (Who Framed Roger Rabbit?) is that the executives vetoed it after a focus group came back with results suggesting that audiences were wary of movie titles containing overt questions.
Fake American: Suffolk-born Bob Hoskins tries to sound Californian, but comes off more like a New Yorker.
Hey, It's That Guy!: Lieutenant Santino is Admiral Motti, aka the Guy Who Gets Choked by Darth Vader.
Mel Blanc voiced pretty much all the featured Looney Tunes that he originated from the actual shorts*
the only voice he couldn't do due to his failing health was Yosemitie Sam's gruff voice
, and this was one of his last times performing as them.
Fun Fact: This movie was the first time Wayne Allwine would voice Mickey and the last time Mel Blanc would voice Bugs. A kind of passing the torch to a new generation, so to speak.
That's Nancy Cartwright as the shoe that Judge Doom destroys to show how the Dip works.
Kathleen Turner is Jessica Rabbit, if uncredited!
Mae Questel returned to voice Betty Boop — almost fifty years after the character was retired.
Charles Fleischer, who didn't have many popular roles outside of this film (he was Dweeb, the dim-witted diplodocus, in We're Back!), managed double duty as both Roger and Benny the cab! He's also Greasy and Psycho, two of the weasels.
The weasel Wheezy is June Foray. She's also Lena Hyena.
Talking to Himself: During the film's car chase scene, Roger Rabbit and Benny The Cab, both voiced by the same actor, scream rapid-fire dialogue at each other.
Eddie Murphy also turned down the role of Eddie. He said in an interview that he regrets it to this day.
One of the early drafts of the film called for Jessica's act to have a cameo of The Wolf to be seen doing similar reactions during Jessica's performance at the ink and paint club. Sounds like this would have been a tribute to Tex Avery's Red Hot Riding Hood, his best known MGM cartoon.
Paul Reubens turned down the role of Roger Rabbit.
Tim Curry auditioned for the role of Judge Doom but Robert Zemeckis, Steven Spielberg, Jeffrey Katzenberg and Michael Eisner found his performance too terrifying.
An early draft of the script included Marvin Acme's funeral. Tom And Jerry were two of the characters scheduled to make a cameo appearance. The scene was dropped due to not getting the rights to the characters.
Similarly, a cameo by the Popeye characters was planned, but cut because the rights could not be secured.
Originally there were twelve weasels. These were cut down to seven (to mimic the seven dwarfs), and finally five, to give them a more prominent role in the movie.
According to IMDb.com, the song that was going to be used as the movie's musical finale in an early script that had Roger die during Eddie Valiant and Judge Doom's final battle was "The Lazarus Heart" by Sting (though the song was written in tribute to Sting's late mother), before the studio changed the ending to have Roger live.
According to Chuck Jones, due to Executive Meddling the piano duel you see in the film is not the original storyboarded version. While it is a memorable scene, who knows how hilarious the original must have been?
In a scenario lifted from classic Looney Tunes cartoon "Show Biz Bugs", all of the audience's praise would have gone to Donald Duck, who'd do absolutely nothing but standing there to receive such acclaim, as Daffy Duck could only gain the attention of Chirping Crickets no matter how hard he tried. In a movie meant to showcase the zany and wild nature of 40's cartoons, you can see how this scenario really didn't fit with the film's atmosphere.
Besides, Donald getting acclaim for anything would've gone against his own character. Having Daffy and Donald sabotaging each other not only fit the movie better, it fit better with Donald and Daffy as characters.
The sequel would've had Eric Goldberg supervise the animation instead of Richard Williams. He was heading the animation test that they showed Michael Eisner to prove they could still pull it off without William's London studio. But the results did not satisfy him, and the other reasons listed in the opening section attributed to its cancellation. ...just imagine every single classic cartoon character with the movement of Aladdin's Genie! Eric Goldberg would eventually head another film with the Roger Rabbit Effect in Looney Tunes: Back in Action for 2003.
In the third draft of the script, instead of Doom dipping the shoe, he was to dip a gopher for bumping into him and soiling his coat. When the gopher complained that he should get a trial first, the weasels take out a briefcase containing a literal Kangaroo Court and call him guilty, with their joeys holding card spelling "Y-O-U-A-R-E-G-U-I-L-T-Y", followed by the gopher getting dipped as Eddie helplessly watched.
Working Title: According to the early original script, the working title was Who Shot Roger Rabbit?, basically because it revealed the manner of how Roger would die before the title was eventually changed, as the studio would not want a character's death to frighten children.
