The song playing over the end credits, "Dancin' Cross the USA" by Lindsey Buckingham, and the photo snapshots, are a reference to the film National Lampoon's Vacation.
When the Amish get on horse back and try to trap Peter, Joe and Quagmire it is a nod to the hunt scene in Planet of the Apes (1968).
Wilhelm Scream: when the roller coaster falls backwards down the track.
In this episode, Seth Green voices the character of an Amish guy. He played a similar comedic Amish character in Sex Drive (2008).
Actress Chloë Grace Moretz said in a recent article in Hunger magazine that she assumed the gag about Legs Go All the Way Up Griffin was directed at her, modeled after a photograph of her in short shorts walking down the street. In the article, Chloe states that the comparison traumatized her and she never fully recovered.