Flags of Japan, Israel, Australia, Canada, Britain, Brazil, up at their country booths except booth likeness France, China, Italy, and Africa don't have flags in Springfield elementary school hall.
Darcy has a mole on her left cheek just like Natalie Portman who provides her voice for the role.
At the beginning of the episode it's revealed that Nelson is of German heritage and that he's proud of it. He holds a dachshund (Dackel/Teckel) and a beer jug, also he's wearing a tyrolean hat from the state of Bavaria in Germany.
In this episode, we learn that Lenny and Carl share a mother. This would indicate that they are possibly half-brothers or their mothers are colleagues.
When the cow in the barn kicked a lit lantern, which set fire to the barn, it makes a reference to what may have caused the Great Chicago Fire in October, 1871. It was alleged that a cow kicked a lit lantern over, which set fire to the farm and then Chicago.
Sign upon leaving town: "Now leaving Springfield, birthplace of Nelson".
The Spuckler Family Tree shows that Cletus's wife Brandine is the child of Cletus and an alien. Also, Cletus and Brandine have twelve children, with one being a sheep and one being a walking hot dog.
The episode reveals that Dolphin "Dolph" Starbeam has Mursi heritage. He has a stone plate in his mouth as typical for this ethnic group.
North Haverbrook has a Hispanic version of the Comic Book Guy and his Comic shop named "Mylar Baggins Comic Book Shop. Baggins is also the surname of Frodo, the protagonist of J. R. R. Tolkien's The Lord of the Rings.
Two of the towns Bart drives past are Ogdenville and North Haverbrook. Lyle Lanley sold monorails to these towns before coming to Springfield in the episode "Marge vs. the Monorail".
The scene in which Bart and Darcy are slurping the same spaghetti, references Lady And The Tramp, when it has the same scene. But Lady and Tramp kiss each other, when they were done slurping that spaghetti, and in the Simpsons, Darcy kisses the dog instead, and both Darcy and Bart laugh.
Coincidentally, Natalie Portman (who voices Darcy) went on to play a character who is friends with a person named Darcy in Marvel's ''Thor" movies. Don Payne, who wrote this episode, also co wrote the screenplay to the first "Thor" movie as well as writing the story to its sequel, "Thor: The Dark World".
Bart is never seen driving again after this episode, despite having a license.
Mayor Quimby couldn't have issued Bart a driver's license, as he doesn't have the authority to change state law. Even if Mayor Quimby did have the authority, he would only be able to propose the change and it would never never pass.
Both Bart and Darcy are under the legal marriage age in every state, also without court approval and/or parental consent, the lowest age you can marry in any state is 18 (except in Nebraska where the age is 19 and in Mississippi where the age is 21).
The minister at Wives "R" Us mentions polygamy, which is also illegal.