Illegally Yours (1988)
Illegally Yours is a 1988 comedy film set in St. Augustine, Florida where a series of comic mishaps take place involving a blackmailer, a corpse, an incriminating audiotape, an innocent woman who accidentally picks up the tape, and a pair of teenage blackmail victims. The film was directed by Peter Bogdanovich with Rob Lowe starring as Richard Dice, the college dropout who came back home to get his act together. The film's theme song was performed by Johnny Cash.
More at Wikipedia.