Acting for Two: Charles Fleischer voices not only Roger Rabbit but Benny The Cab and the Toon Patrol's Greasy and Psycho. Veteran voice actress June Foray provides the voices for both Wheezy and Lena Hyena.
Bowdlerise: When the movie first came out, there was a scene where Jessica Rabbit was tossed from Benny the cab and her skirt gets hiked up, revealing that she's not wearing underwear. On home video and laser disc, the scene was reanimated so that way Jessica is wearing white panties. On DVD, the scene was reanimated so that way Jessica's skirt is longer and her fall is a bit more graceful.
Keep Circulating the Tapes: The German TV version is probably the only print in the world that has the original version of that scene (and the original scene of Baby Herman sticking his finger out while walking underneath a live-action woman's skirt and gazing up it lecherously. The new version keeps the scene in, but digitally removes the finger). The older versions are out of print.
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 see 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.
It's also worth noting that Porky Pig and Tinkerbell share the last bit of the movie.
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.
Also, Whitechapel-born Alan Tilvern as movie mogul R.K. Maroon.
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 shortsnote 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.
That's Nancy Cartwright (Bart Simpson, Ralph Wiggum, Nelson Muntz, Kearney Zzyzwicz, and Maggie Simpson) as the shoe that Judge Doom destroys to show how the Dip works.
Kathleen Turner is the speaking voice of Jessica Rabbit, and Amy Irving provides Jessica's singing voice. Turner wasn't credited at all, and Irving is credited for her performance of "Why Don't You Do Right."
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 Parasaurolophus, in We're Back!), managed double duty as both Roger and Benny the cab! He's also Greasy and Psycho, two of the weasels. (He would have a role in Robert Zemeckis' next movie, Back to the Future Part II.)
The weasel Wheezy is June Foray. She's also Lena Hyena.
Playing Against Type: Christopher Lloyd as Judge Doom. This one of the few movies where he plays a truly evil and ruthless villain, although this was made around the same time as most of those other films.
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.
Bill Murray was an early favorite of both Spielberg and Zemeckis for Eddie, but, as Murray is notoriously difficult to contact, they were unable to get ahold of him. Murray claims that had he known, he would have taken the part.
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.
Or did he? It turns out that, according to new footage obtained from an '80s special titled Disney Studio Showcase, producers originally wanted Reubens to voice Roger. Reubens was quite a bit okay voicing the character... for a while. Besides that, it was also revealed that originally Jessica Rabbit was hardly in love with Roger at all.
Tim Curry auditioned for the role of Judge Doom but Robert Zemeckis, Steven Spielberg, Jeffrey Katzenberg and Michael Eisner found his performance too terrifying (just like what happened when Tim Curry went for the role of The Joker on Batman: The Animated Series).
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.
Also, in the early script, toons weren't immortal and could get killed by any kind of attacks like in the book. This, too, was changed to the fact that toons can only be killed by the Dip.
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.