Who's the Caboose?.

A documentary team gets a grant to do a film on a rare fatal disease that is attacking homeless people. However, they quickly find the film too depressing. Ducking into a nightclub, they discover a young Manhattan comedienne and decide instead to follow her as she makes the circuit of auditions in L.A. as she tries to get a TV pilot. Unfortunately, she has failed to tell her boyfriend of this move. He decides he will trail her out west. There, the boyfriend runs into an old friend who has already made a break on a TV pilot. Seizing the opportunity, the actress turns her attentions to the established actor. However, the actress goes nowhere in auditions, but her ex-boyfriend is suddenly noticed and becomes the next hot prospect.