The old hippie who interrupts Homer and Mona's goodbye by yelling "This electric van has only got 20 minutes of juice left!" was seen in the 1960s flashback as the one who was commanding the sabotage on Mr. Burns' biological warfare laboratory.
Mona's "D'oh!" when she bangs her head on the top of the van was done by Pamela Hayden, as Glenn Close couldn't do it properly.
Due to the emotional tone of the final scenes, Matt Groening and his co-workers insisted that the closing credits be shown in full (with no squeeze-credits or voice-over announcements for other shows).
Abe Simpson is watching Super Bowl III, which featured quarterbacks Johnny Unitas of the Baltimore Colts and Joe Namath of the New York Jets. The Jets, led by the long-haired, hard-partying Namath, defeated the Colts, led by the crew cut-wearing, strait-laced Unitas, 16-7. Incidentally, both men appeared on The Simpsons, Unitas in Homie the Clown and Namath in Bart Star.
Mona mentions that she worked a number of jobs while on the run, including "marketing Jerry Rubin’s line of diet shakes, proofreading Bobby Seale’s cookbook, and running credit checks at Tom Hayden’s Porsche dealership." Rubin, Seale and Hayden were three liberal radicals from the 1960s and Rubin did indeed have a line of diet shakes, and Bobby Seale did write some cookbooks. However, Tom Hayden never owned a Porsche dealership.
The Grave that Abe Simpson lied to Homer about where Mona was buried belonged to Walt Whitman.
The radicals use a Spiro Agnew alarm clock, which is based on a real item.
When Mr. Burns drives a tank towards the Simpson house, he is wearing oversized headgear. This is a reference to a public relations stunt by Michael Dukakis during his presidential campaign in 1988, which backfired on him as Dukakis looked awkward wearing a helmet that looked too big for his head and was derided by critics and comedians as "Dukakis in the tank".
When Mr. Burns plays a tape of "Ride of the Valkyries", it has been recorded over by Smithers with "Waterloo" by ABBA, a reference to Smithers' suspected homosexuality (ABBA have a large gay following) and to the helicopter beach attack scene in Apocalypse Now, in which "Ride of the Valkyries" is famously played.
Originally, the song Smithers taped over Ride of the Valkyries with was WHAM!'s Wake Me Up Before You Go-Go, but the producers couldn't get the rights to the song in time. Coincidentally, WHAM! (or, rather, the lead singer, George Michael) also has a gay following, so whether or not the original song was used wouldn't change the character subtext of Smithers.
Maggie is shown dancing in her diaper and covered in slogans and it is a parody of the filler scenes of Laugh-In in which Goldie Hawn and other female castmembers like Ruth Buzzi and Jo Anne Worley danced in a bikini with slogans and drawings painted on their bodies.
The two FBI agents are Joe Friday and Bill Gannon from Dragnet. Bill Gannon is voiced by Harry Morgan, the man who played Gannon in the original series.
While lying on the couch, Mona is reading Steal This Book by Abbie Hoffman.
After Marge yells Patty and Selma to "Get out of here you ghouls!" she says "Ay yi yi yi yi!" Alpha 5's catchphrase from the Mighty Morphin Power Rangers.