Duke and his attorney embark on their journey to Las Vegas with loftier goals than simply writing an article about the Mint 400. They are in search of the American Dream and generally want to escape from L.A. because, as Duke says, "Every now and then when your life gets complicated and the weasels start closing in, the only real cure is to load up on heinous chemicals and then drive like a bastard from Hollywood to Las Vegas" (12). However, it is their commitment to assigning a deeper meaning to this epic journey and Duke's confidence that he will get his work done that proves to be their ultimate undoing, which Thompson foreshadows throughout the novel.
1) "No, this is not a good town for psychedelic drugs. Reality itself is too twisted" (47).
Duke's observation here foreshadows all of his close brushes with the law over the course of the novel and his ultimate realization that the American Dream is just as empty as his hallucinations.
2) "Something ugly was about to happen. I was sure of it. The room looked like the site of some zoological experiment involving whiskey and gorillas. The ten-foot was shattered, but still hanging together -- bad evidence of that afternoon when my attorney ran amok with the coconut hammer, smashing the mirror and all the lightbulbs" (181).
This foreshadows the maid coming into Duke's room, after which he and his attorney must figure out a way to convince her not to turn them in.
3) "The important thing is to cover this story on its own terms; leave the other stuff to Life and Look-- at least for now" (57).
Duke's rumination here foreshadows the format of his eventual coverage of the Mint 400 - a series of Rolling Stone articles that he compiled into Fear and Loathing in Las Vegas. Furthermore, "cover this story on its own terms" is essentially a definition of Gonzo journalism, a genre that Thompson pioneered.