Econo Airline pilot Rusty eavesdrops on a conversation in which his wife Debbie discusses how bored she's become of the routine in their marriage, exemplified by the usual Sheboygan cabin they rent every year around Memorial Day, Rusty decides to surprise her and their sons with something new -- a cross-country road trip from Chicago to So-Cal's Walley World, just like he had when he was a lad. Renting a similar family wagon in the Tartan Prancer, which contains features seemingly just to have them, the family of four set off for a whole series of misadventures, including road rage incidents, attempts at public sex, and a treacherous white-water rapids excursion with a suicidal rafting instructor at the nadir of his depressive state.