As the curtain rises on this exhilarating adventure, we find Pete Stancheck (played by Cloris Leachman) inheriting his uncle Jim Douglas's treasured possession, Herbie. He embarks on a journey to recover Herbie in the bustling Puerto Vallarta, Mexico, accompanied by his loyal sidekick, Davy "D.J." Johns (portrayed by Charles Martin Smith). Their escapade takes a wild turn with the assistance of a comically mischievous pickpocket named Paco. Together, the trio becomes embroiled in a chaotic pursuit after Paco deftly lifts their wallets right from under their noses. Unbeknownst to Pete and D.J., Paco has inadvertently foiled the malevolent plans of a group of villains who are scheming to steal gold from ancient Inca ruins.
Fate intertwines their paths further when Paco, stowing away in Herbie's hood, finds himself aboard the magnificent Sun Princess cruise ship headed for Rio de Janeiro. Onboard, Pete and D.J. cross paths with Melissa, a spirited anthropology student, and her vivacious aunt Louise (played by Harvey Korman), who is determined to find a suitable mate for her niece. As Herbie wreaks delightful havoc on the ship, Pete seizes the opportunity to impress Melissa’s aunt and secure sponsorship for their racing dreams.
However, clever Paco has his own schemes. As he hides from the crew of the ship, he must rely on his wits to avoid getting caught by the vigilant Captain Blythe (portrayed by John Vernon). With a dash of ingenuity and with Herbie's assistance, Paco orchestrates a daring getaway from the ship’s hold, igniting mayhem during the costume party. Captain Blythe, taking desperate measures, commands that Herbie be tossed into the ocean, while Pete, Melissa, and Aunt Louise are disembarked at the next port.
Paco soon finds himself back at square one, only to encounter Herbie, who resurfaces from the water like a phoenix. An unlikely alliance forms as Paco exploits his pickpocketing skills to turn Herbie into a makeshift taxi service. Yet, their newfound success is short-lived as the fearsome gold thieves reemerge, demanding that Paco surrender the film revealing the location of the ancient treasure.
As tension heightens and stakes rise, Paco must cleverly outsmart the villains while Pete, Melissa, and Aunt Louise unite their efforts in search of their rogue friend. Their makeshift heroics come in the form of a rickety bus commandeered by Melissa, as they embark on a whirlwind adventure brimming with thrilling chases, audacious escapes, and heartfelt camaraderie.
During a riveting chase in a bullfighting arena, Herbie faces off against a formidable bull and, with extraordinary bravery, successfully eludes the beast, also rescuing Paco in the process. Meanwhile, as the group navigates unforeseen obstacles – including a rainstorm that strands them in a small village – they learn that the thieves are intent on claiming a massive golden disk hidden among the ruins.
Abandoned by his former captors, Paco remains determined as Herbie's instincts guide him to their friend's whereabouts. With Paco revealing the villainous schemes of the thieves, Herbie leaps into action, intercepting the gold and stashing it safely away.
The adventure continues as they head for the next big town, where Captain Blythe and Aunt Louise seek help, but things take a perilous turn when the villains reappear. Paco and Herbie, robust and ready, rally to confront the evildoers in a spectacle involving cleverly thrown bananas, ultimately leading to the thieves’ capture by authorities.
The group finds solace back on the majestic Sun Princess, rejuvenating their plans to enter a refurbished Herbie into the Brazil Grand Prêmio, with Paco gleefully taking the wheel. As Aunt Louise once again vies for Captain Blythe’s attention, he remains distracted by a passing schooner. D.J. finally inquires about Paco's quirky habit of calling Herbie “Ocho,” leading Paco to explain the delightful math behind the name: 5 + 3 equals 8.
As the group lifts glasses in a toast to Herbie’s hopeful triumph at the Brazil Grand Prêmio, Paco flashes a victorious thumbs-up, solidifying their bond and cementing the memories of their incredible journey.
