This actually becomes a running gag, Agent Flemming orders cavity searches for nearly every person they interogate during their investigation, including the elderly passengers on the America Tours bus, Mr Anderson and Butthead.
The road trip montage on the America Tour bus, which includes such gems as Beavis and Butthead being more interested in a donkey taking a crap than the Grand Canyon, them laughing at various dirty road signs, such as "Butte" and "Wipe" and "Bald Knob", and headbanging to the montage music.
When they arrive at Yellowstone National Park, the duo are absolutelymesmerized by the motion controlled flushing for the park urinals, to the point where they stay in there so long that the bus leaves without them.
Funnier when you consider that moments before, they were dismissing the Old Faithful geyser.
Ranger: There are over 200 active geysers in Yellowstone Park. Old Faithful here is one of the largest. During an eruption, the geyser can reach as high as 200 feet. Butt-head: So? Ranger: The - the geyser shoots out over 12,000 gallons in a single eruption. Beavis: That's not that much, really.
When the two end up on a bus full of nuns on their way to New Mexico, Beavis is taken in by having the bible read to him, since "there's this talking snake, and a naked chick, and a dude who puts a leaf on his schlong".
The "He said anus" exchange between the boys and Mr. Van Dressen.
The deleted scene of Beavis using the Declaration Of Independence as toilet paper. Its even more hilarious that there was a security guard standing right there, who didnt notice Beavis smashing the display case with a flagpole and stealing the document until the alarm sounded.
The montage of the two arriving at the luxurious hotel and casino theyre staying at, and spending most of it staring and giggling at a topless egyptian statue, to the tunes of Red Hot Chili Peppers Rollercoaster Of Love.
Bill Clinton giving a touching, grateful speech to the two after they foiled Muddy's and Dallas plot. Their reaction?
Butthead: "Huhuh, he said extend."
Beavis and Butthead fighting over who "gets to go first" with Dallas. Its even more hilarious that Beavis doesnt have any pants on during the brawl.
When the two are about to die of dehydration in the desert, they spend what may be their last few moments alive... giggling at two vultures having sex.
Later in that same scene, Beavis has his Mushroom Samba from eating a peyote cactus.
Their escape from Muddy's car, while its moving on the interstate. This involves Butthead pushing Beavis out of the trunk and then falling out himself when the car hits a road bump. They end up causing a huge car pileup, including crashing Tom Andersons trailer.
Beavis/Cornholio having A Date with Rosie Palms in Anderson's camper, complete with music that makes the scene ten times funnier. And Anderson's reaction when he finds Beavis.
When Fleming demands that Beavis show him the unit, he snaps out of Cornholio mode just long enough to say "Why does everyone want to see my schlong?"