In this episode, Richie has a party to celebrate Hawaii becoming a new state. However, Hawaii became a state in 1959, and the year of this episode is 1956.
Rosemary: Who do you think you are, checking out my niece Kathleen?
Fonzie: No offence, nice lady, but when you buy a car, you check under the hood.
Rosemary: Listen, ducktail...
Fonzie: Ducktail?
Richie: (holding back Fonzie) Take it easy, take it easy. She's a woman, okay?
Rosemary: If anybody checks under Kathleen's hood, they're going to get a dipstick up their nose.
Howard: Prejudice is stronger than cool.
Fonzie: Stronger than cool?
Howard: Yeah, but don't be upset. You see, prejudice had a big head start. It started with the cavemen. Cool's only been around since Benny Goodman.