Originally, Moby's version of the James Bond theme was playing in the background when E.L. drove the car over the bridge. However, Director Todd Phillips later switched it to a 'generic' song, because the budget didn't allow him to use the Moby song.
The Ford Bronco in the exploded car scene with Fred Ward was rented from the actual safety crew that was there for the jump scene and car explosion scene. The Transportation Director thought the personal vehicle of one of the paramedics would look good in the movie as a rescue vehicle. It was used in the subsequent scene where Fred Ward is investigating the burned out car shell. The scene was filmed in Monticello Georgia. The transportation staff lettered up the Bronco with magnetic door signs denoting it to be a Pennsylvania K-9 Search and Rescue vehicle. It even got a authentic government tag. Steven Spielberg put his Filet Mingon and Lobster Tail lunch tray on the Bronco's hood costing the production an extra $800 to repair the scratches.
Shares a similar plot with the 1998 film, "Overnight Delivery." In both stories, a young man in a long distance relationship gets anxious after not hearing from his girlfriend in a while. He sends her a package with proof of his own infidelity and ends up chasing the package across the country to retrieve it before she opens it.
When E.L. asks for "help" from the nurse working at the sperm bank she says, "The best results seem to be obtained through fantasization accompanied by masturbation followed by ejaculation." This line was taken from a similar scene in The Right Stuff (1983), where Gordon Cooper asks for help from Nurse Murch.
Each College in the movie, other than the University of Tennessee, is altered from names of real colleges. For example, University of Ithaca does not exist but is supposed to spoof Ithaca College and Cornell, neither does University of Austin which is a spoof of University of Texas, or University of Boston which could spoof Boston College, or Boston University, or most likely University of Massachusetts Boston
When E.L. (Seann William Scott) gets a prostate check up at the sperm bank by the nurse (Marla Sucharetza), the gloves that she wears are "Evolution One" latex gloves as indicated by the box when he enters the check up room. The gloves are made by the company Microflex.
The trivia item below may give away important plot points.
After the classic River Jump scene, when the group gets lost and is forced to jump the river because no other roads are around, (specifically around the 36 minute 10 second mark), A road appears to be insight behind Josh just into the forest.