"Don't worry about the structure, I know to compress and re-arrange the plot a bit to give a perfectly acceptable movie-type structure: making it into one all-inclusive trip instead of the several voyages coast-to-coast in the book, one vast round trip from New York to Denver to Frisco to Mexico to New Orleans to New York again. I visualize the beautiful shots could be made with the camera on the front seat of the car showing the road (day and night) unwinding into the windshield, as Sal and Dean yak. I wanted you to play the part because Dean (as you know) is no dopey hotrodder but a real intelligent (in fact Jesuit) Irishman. You play Dean and I'll play Sal (Warner Bros. mentioned I play Sal) and I'll show you how Dean acts in real life…we can go visit him in Frisco, or have him come down to L.A. still a real frantic cat…, "

http://www.dharmabeat.com/movie.html

And it does look like they just let Kristen Stewart be Kristen Stewart without invoking either the characterization in the novel, or the real LuAnn. Sigh. And then after all this marketing to the mopey, illiterate Twihards they don't even let her speak in the trailer.

If they are going to talk about the female characters I'd like to hear more about Kirsten Dunst as it's arguable Camille/Carolyn is more important and relevant to Neal/Dean than Marylou.