The Danza: Contrary to popular belief, Scat Cat was not originally intended to be voiced by Scatman Crothers, but by Louis Armstrong. It was, in fact, a coincidence when Armstrong turned the role down and it ended up going to Crothers, who just so happened to have a similar nickname.
Madame is Ellen from Mary Poppins, which is also set in 1910. (Disney sure loved that time period in the olden days, didn't they?)
Prop Recycling: Many of the vehicles in the film are actually recycled from 101 Dalmatians, especially the Baduns' truck and the moving van. The vehicles in that film were white models with outlines drawn on the edges, filmed with a stop-motion camera and then photocopied onto cels. Because of time and money constraints, rather than give build new models for the milk truck and the baggage van, Disney simply reused them for these roles in this film, respectively.
What Could Have Been: Scat Cat was originally written with Louie Armstrong in mind, with his original name being Satchmo Cat. Unfortunately, illness kept Louie from being able to play the character and the character was recast with Scatman Crothers and given the "Everybody Wants to Be a Cat" song replacing the one the Sherman Brothers wrote for Armstrong, "Le Jazz Hot".
There were plans for an "The Aristocats II," and was supposed to be a direct-to-video sequel. While the first film had the kittens’ nemesis as a misguided butler intent on stealing their fortune, the sequel created a similar dynamic by pitting them against a jewel thief on the open seas aboard a luxury cruise ship. There was also a young kitty love interest for Marie who became the focal character of the film. The ship would travel from places like France, Scotland, England, Spain, etc, thus creating a creating a new atmosphere of different places in the early 1900s. It was scheduled to be released in 2007, but the production was canceled in early 2006 after Disney acquired Pixar.
There were also plans for an "Aristocats: The Animated Series." way back in 2003. Marie and her brothers Berlioz, and Toulouse would be turned into teenagers. And would've given Marie (Who was supposed to be the main character of this new "Aristocats" show) someone new to bounce off of. They invented this teenaged cat similar to O'Malley the alley cat, called Delancey, who could dance like a combination of Justin Timberlake and Usher. And then to round out the cast "the Street Cats" were created. The basic idea here was to reinvent "The Aristocats" so that this franchise would then appeal to your typical Disney Channel/Toon Disney watcher. But when Disney bought Pixar in 2006, it was cancelled along with the "Aristcats II" film.