3What is the name of the hotel that the Griswolds are registered at just after they arrive in Las Vegas?
Answer: The Mirage
When the limo driver opens the door for Clark Griswold, he tells him, 'Welcome to the Mirage'. The name of the hotel is referenced after that more than once.
6Which actor or actress receives 3rd billing in the opening credits?
Answer: Randy Quaid
Randy Quaid recreates his Cousin Eddie role for the third time in the series, and he arguably steals the spotlight from all of the other players in this movie. Probably because Cousin Eddie has a plate in his head.
11As Clark Griswold is absent-mindedly driving through his neighborhood, leafing through his Vegas brochure, what hotel is featured on the front cover of the brochure?
Answer: The Mirage
This is appropriate as The Mirage is the hotel/casino where the Griswolds begin their stay in Las Vegas.
12In the sequence where the Griswolds are initially driving down the Vegas strip in a limo, Ellen sees a sign that displays what hotel is host to Wayne Newton's show?
Answer: MGM Grand
You can't miss the big green and white lights and the words MGM Grand next to Wayne Newton's name. However, Wayne Newton did break with his contract and sign with Stardust a few years after this film was released.