Meg and Paul travel to Sofie's alma mater Sacred Heart Catholic School in Winnetka, Illinois, which is a real school about 20 miles north of downtown Chicago.
Sofie's room at the Lakeview is back to room number 203.
The woman who picks up Holden and Carly while hitchhiking has an Illinois license plate reading KGF1698.
Parker Snyder: See, here's the difference between us -- I don't brag about my talents. And you say that you have some, which you don't, like kissing.
Liberty Ciccone: Well, I want a rematch.
Parker Snyder: At what, kissing or tennis? 'Cause I'm a pro at both.
Liberty Ciccone: Ooh! You don't want to know what you really are.
Parker Snyder: Uh, the winner? Guy that beat you?
Liberty Ciccone: No, the guy who ends up alone.
Liberty Ciccone: Um, well, thanks for the game, tough guy. Guess I'll see you around campus.
Parker Snyder: It's not a game. It's called a match. Oh, my God. Can I sound like a bigger dweeb?
The song that plays while Parker and Liberty are playing tennis is Figure it Out by Maroon 5.
Uncredited speaking parts include an Al's shift manager named Marty and a woman who gives Holden and Carly a lift.
The on-location scenes at Camp Chapawee, Oakdale High School, and the tennis courts were taped using hand-held cameras.
Liberty Ciccone: Oh, wow! You're -- you're just a real, regular Andy Roddick, aren't ya?
Andy Roddick is a professional tennis player who was formerly ranked number one in the world.