A noir isn't a noir without one shocking twist after another hitting the viewer in the last ten minutes, like one of those cartoon sequences where a character ends up ricocheting around a room, being set on fire, electrocuted, and having a refrigerator dropped on them in rapid succession.
Roger Rabbit delivers on all counts.
The cartoon sequence is at the beginning. We're here to talk about the end. The first thing the ending does is answer the title question: Who Actually Framed Roger Rabbit? It was Judge Doom. It also answers the question, Who Killed Eddie's Brother? (Not a good title for a movie.) It was Judge Doom. And finally, it answers the question Where is Marvin Acme's Will?
The answer to this one is not "It was Judge Doom."
In a bit of comic genius, the random disappearing ink gag from early in the film returns. And so does the ink. The disappearing ink reappears on Eddie's shirt, days (in movie time) after Acme initially squirted Eddie with it. That leads him to realize that Acme, the king of gags, wrote his will in disappearing-reappearing ink.
The will reappears in the nick of time, saving Toontown from a terrible fate. Comedy's all about the timing. Speaking of timing, Porky Pig's is incredible. He shows up at the very end to send the film to its credits with his trademark stuttering "Th-th-th-that's all folks!" It's not over until the fat pig says it is.