It's true that only snippets of the music appear in the movie, except for a few times, like the instance you mention where they find the bunny. But also when Gordon plays the accordion, that is a longer song, and of course at the end, when the music comes up as Mac gazes out at downtown Houston, and the credits begin. To really appreciate the music, you need to listen to the soundtrack. According to imdb, the soundtrack made more money than the movie did!!