*NikkiBell* said:
Years ago, this movie was done by a company not associated with Disney...Touchstone, I believe.
Touchstone Pictures was a part of The Walt Disney Company when "Who Framed Roger Rabbit" (1988) was made, and Touchstone Pictures is still a part of The Walt Disney Company. The Touchstone brand was started by Ron Miller when he was CEO of Walt Disney Productions. This brand would allow Disney to make movies that would not have to be family movies. The first Touchstone movie was "Splash" (1984). When Wells, Eisner, and Katzenberg arrived, they leveraged the Touchstone brand in a big way.
"Who Framed Roger Rabbit" is interesting in that it was a joint venture between Touchstone Pictures (The Walt Disney Company) and Amblin Entertainment (Steven Spielberg).
The Roger Rabbit's Car Toon Spin at
Disneyland (1994) and the three Roger Rabbit short subjects (1989-1993) are not new. They go back to the years soon after "Who Framed Roger Rabbit" was made.
That relationship between Disney and Amblin went sour, and that's why there's never been a sequel. I suppose that could change now that Eisner is gone. I don't know where the OP "read that there is a sequel in the works." I'm not aware of any such sequel, and I don't expect to see one.
The movie's fictional R.K. Maroon cartoon characters were joined not only by characters from Disney and Warner Bros., but also from MGM, Paramount (Max Fleischer), and Universal (Walter Lantz). Having characters from various studios on screen together was a key part of the movie's premise. It took some persuasive negotiations to pull off the licensing.