The Ford Excursion's one seriously big SUV with a seriously big rear window. It's the perfect size for writing all sorts of messages — in this case, word that Nikki knows about Dave's affair. Good thing for Dave the Excursion can easily double as a studio apartment.
A certain distinguished member of Congress from New York must be happy right now he doesn't own a Ford Expedition. Although his Nissan Pathfinder's pretty big too.