Wayans and Sandler play fast and loose with buddy-movie cliches, and the result is an often amusing mess. Wayans plays a street-smart detective; Sandler is a sad-sack potential federal witness he must protect. Complicating the comic tension is the fact that they used to be friends — until the undercover Wayans busted Sandler, who then accidentally shot him. Once they’re reunited, Bulletproof puts them through slapdash chase scenes and decidedly less spontaneous bond-while-they-bicker interludes. Their odd-couple chemistry doesn’t quite transcend the crudely processed plotting, but seeing them on video does improve the experience: When Sandler warbles ”I Will Always Love You” in his best (worst?) Cajun Man- meets-Whitney Houston voice, you can fast-forward through it, in blissful silence.