Superbug, the Wild One (1973)

Jimmy Bondi and his miracle yellow VW Beetle Dudu are asked by their boyfriend Aldo to support him at a car show in Liverpool. After the show it turns out that the organizer Ivan Leskovich made off with the proceeds. Dudu and his friends give chase. Leskovich's trail leads via London to Switzerland, but thanks to Jimmy's lack of navigational skills, the friends first end up in Portugal...