Audio problem: Volkswagen Beetles had a very distinctive "putt-putt" engine noise. In every scene with the bad guy following Ryan and McBride in a VW Beetle, the sound effects dubbed in post-production belong to a much larger, standard American car, and not to a VW at all. (00:26:00)
Revealing mistake: Not only is the stunt double's face visible in several shots during the apartment fight scene, the man is also noticeably taller and heavier than Robert Wagner, and is wearing a really bad wig.
