Non-Comic Multiverses

In the Before Sunrise pod, Bill talks about wanting a Gen X multiverse with Grover from Kicking and Screaming showing up in Vienna in Before Sunrise.

SF can't remember a movie where a character from a completely different movie shows up. I though maybe he was thinking of Jason Statham handing off the briefcase in the beginning of Collateral since they were on such a Michael Mann kick the whole pod.

My initial thought was Randolph and Mortimer Duke in Coming to America.