Clark tells Rusty and Audry that he hardly recognize them anymore, a reference to having different actors play the Griswold children in each of the four movies.
Clark's line, "It's all part of the act Rusty," is a reference to the Dodge City bar scene in National Lampoon's Vacation (1983).
Filmed during the busy tourist season, from mid-June, through late September of 1996.
The only film in the National Lampoon's Vacation series not to be written by John Hughes.
Although it was executive produced by 'Matty Simmmons', it was the only "Vacation" movie series (starring Chevy Chase) not to feature 'National Lampoon's' in its title. It would take another six years for the direct to DVD spin-off film "Christmas Vacation 2" to be released and be credited as "National Lampoon's."
Clark's middle initial W. stands for Wilhelm.
We learn in this Vacation film, from the scene where Clark proposes to Ellen, that Ellen's has two middle names: Pricilla and Ruth, and that her maiden name is Smith.
The four vehicles Rusty won throughout the movie that he and his family drove home at the end were: A 1996 Ford Mustang Convertible, 1996 AM General Hummer, 1996 Ford Aspire and a 1996 Dodge Viper RT/10
In the original draft for Vegas Vacation, the Griswold's do not stay at the Mirage Hotel. They stay at the Walley World Hotel and Casino, and Roy Walley was a part of the script. This is a reference to the Griswold's vacation destination from the first film. The Griswold's house is located on the same block as the Murtaugh House from the Lethal Weapon movies.
The Keno scene at the end of the film takes place at the MGM Grand Hotel Casino. The family is seen entering through the original "lion's head" entrance, which was present when the casino was first built. This entrance has since been remodeled to look like "regular" doors, with a lion statue on top. The keno section of the casino is no longer there either.
One of the dealer's in the odd ball casino Clark and Eddy go to is also the blackjack dealer in the movie 'Rainman'.
Although depicted as a joke, the children's card game of War is a real casino game.
Only Vacation film that does not include a reference to the Walley World amusement park (the original film revolved around visiting the park, Clark had a T-shirt for it in European Vacation, and Clark and Eddie drank egg nog from Marty Moose (mascot of the park) glasses in Christmas Vacation.)
The living room that Wayne Newton and Ellen have dinner in, is Wayne's actual living room from his home in Las Vegas. His home was also on MTV’s "Cribs" (2000), where that same room is featured.
The happy family in the center of the Las Vegas brochure is a picture of director Stephen Kessler and his family.