Ford Fairlane (Andrew Dice Clay) is seen sitting on a beach smoking as the film opens. A flashback initiates, showing a roaring crowd at a concert given by fictional popular heavy metal band The Black Plague. Lead singer Bobby Black (Vince Neil) makes an eccentric entrance down a zip-line onto the stage and begins performing. Shortly into one of the band's songs, Bobby Black collapses on stage and dies.
After the lead singer of The Black Plague is murdered onstage, shock-jock Johnny Crunch (Gilbert Gottfried), an old friend who came west with Fairlane, hires Ford to track down a mysterious teenage groupie named Zuzu Petals, who may have a connection to Black's death.
Soon after hiring Fairlane, Crunch is electrocuted on the air. The world's hippest detective soon finds himself trading insults with ruthless record executive Julian Grendel (Wayne Newton), a clueless cop and former disco star (Ed O'Neill), a merciless hit man (Robert Englund) and countless ex-girlfriends out for his blood. Aiding and abetting Fairlane is loyal assistant Jazz (Lauren Holly) and a hip record producer (Morris Day) at the head of a bizarre lineup of suspects, victims, beautiful women and a koala as he finds himself hip-deep in the case of his life.
The Macguffin of the film is three data CDs which, when read simultaneously, detail the illegal dealings of Julian Grendel, who was getting rich bootlegging his record company's music and murdered Bobby Black when he found out Black had acquired the CDs with the incriminating evidence.
The first disc was with Colleen Sutton, the second with Zuzu Petals, and the third disc was hidden under the star for Art Mooney on the Hollywood Walk of Fame.

Question: Where was the third secret data CD hiden? 
Answer: Under the Art Mooney's Walk of Fame star. 
Alternative answer: It was hidden under Art Mooney's star on the Hollywood Walk of Fame.