During the opening credits, the voice of deejay Surf Sam (Dave Sebastian Williams) from radio station KBLA announces the impending arrival of Halloween night 1965, which brings with it the melancholic news that Tubby's Drive-In—a beloved hangout of the Hollywood Knights—is closing its doors for good that very evening. An egg suddenly splatters across the name of director Floyd Mutrux.
The leader of the Knights, Newbomb Turk (Robert Wuhl), pulls off a notorious prank involving a dead body on an unsuspecting elderly woman, with the help of a friend cleverly concealed under a tarp atop the borrowed 1965 El Camino from his older brother. Meanwhile, Sally (Fran Drescher) and her friends lounge by the pool—some even sunbathing topless—where Newbomb captures candid photos until they realize he’s there and chase him off.
Officer Bimbeaux (Gailard Sartain) and Officer Clark (Sandy Helberg) meet with their police chief, who cautions them against escalating tensions on this last night at the drive-in. A quick glance reveals the Knights have already vandalized their patrol car with spray paint.
As night falls, three members of the Knights—Wheatly (Randy Gornel), Shorty (Glenn Withrow), and Simpson (P.R. Paul)—gather at Tubby's Drive-In, questioning the wisdom of borrowing the El Camino. Simpson promises to bring along his custom rail car for the night’s adventure.
In a humorous exchange, Clark muses to Bimbeaux about whether he'd look good in a mustache while singing along to Lawrence of Arabia. Amidst their banter, the Knights enact a cheeky initiation rite requiring their pledges to strip down and retrieve some tires from the trunk—while also requesting a song from DJ Doctor J, who eventually takes over the airwaves.
The plot thickens as the Knights spy from a tree as Sally and her friends arrive at a secret location for a wardrobe change. Just as they remove their bras, Newbomb's clumsiness exposes their hiding spot, causing the girls to scatter as police swoop in.
At nearby Smitty's Auto Shop, fellow Knight Duke (Tony Danza) chats with his carhop girlfriend, Suzie Q (Michelle Pfeiffer), about her upcoming screen test and the challenges of juggling her aspirations with her job. Amid an array of kooky characters, the Iron Box Twins (Joyce Heiser and Roberta Wallach) arrive for burgers, only to be interrupted by Newbomb's ridiculous rendition of "Volare".
As the night unfolds, the antics escalate. The Knights launch a series of pranks, cheeky encounters, and absurd performances at the school pep rally while remaining a step ahead of the police, whose attempts to enforce the law seem forever thwarted by the Knights' hijinks.
By 1:00 am, as the festivities wind down, Duke and Suzie affirm their love amidst the chaos, while new Knights are initiated in the trials of the evening. Newbomb and his companions scramble to pull off one last desperate stunt at Tubby's to earn their jackets. The camaraderie echoes strong, even as time slips away from their carefree youth.
Ultimately, the night culminates in an unforgettable party where the memories and moments resonate deeply—capturing the spirit of an era, vibrant yet fleeting, with Tubby's Drive-In dimming its lights for the last time as the credits roll.
