The original ending was shot in full, screened for a test audience, and thrown out. What replaced it brought in John Candy, a line that ended up on t-shirts, and a continuity problem nobody could hide: the boy playing Rusty had grown three inches between the two shoots.

This video covers 25 production secrets behind the 1983 road comedy that launched a five-film franchise. Among them: the Chicago snowstorm that gave John Hughes the short story it came from, the rewrite Harold Ramis and Chevy Chase carried out on his first draft, and the deliberately hideous station wagon built to parody Detroit's family cars, including the long-running argument over who designed it. Also covered are Imogene Coca's reluctance to play Aunt Edna, Christie Brinkley's first work in front of a camera, the cross-country shoot that followed the Griswolds' own route, and the fifty-foot desert jump that wrecked the wagon for the rest of the picture.

Later sections look at the matte paintings and racetrack parking lot that stood in for Walley World, Harold Ramis's uncredited voice appearances, Lindsey Buckingham's theme song, a deleted Arizona sequence, the certificate the film carried and how that shaped its audience, its opening weekend against the summer's biggest holdovers, the way the discarded ending resurfaced six years later, and the broadcast rights deal that nearly doubled in price once the movie became a hit.