Continuity mistake: After Bobby Darin loses the Academy Award for supporting actor, he and Sandra Dee argue and threaten to leave one another. Sandra Dee jumps into her pink '63 Cadillac Coupe Deville and roars away as Bobby Darin jumps into his red '61 Cadillac Convertible and futilely tries to start it. The car's battery fails, and we see the four headlights flicker and go dark. Enraged, Bobby Darin jumps out of the convertible and begins smashing the car with a golf club. When he starts smashing out the headlights, all four lights are now glowing brightly.
Audio problem: In the very first scene of the movie when Bobby is recreating his performance at the Coconut Grove, the actions of the band are out of sync with the music we hear. (Bobby is in sync, but the band is not.) Watch the hands of the drummer and the band leader: The entire scene is out of sync, but when the drummer moves to the ride cymbal you can easily see he is ahead of the music, and when the band leader gives the band cues for accents, his hand movements are behind the music and therefore happen too late.
Factual error: A scene in the second half of the film pans up over the top of the Flamingo hotel/casino facing north up the Vegas strip. The Caesars Palace sign is to the left (west) and north of the Flamingo are the Sands, the Dunes, and the Frontier casinos in that order. The Dunes hotel/casino was never located between the Sands and the Frontier. It was in fact one of the southernmost located casinos on the strip at that time and would have technically been behind, southwest of, the Flamingo in this scene.