Cadillac Man

Cadillac Man is a 1990 comedy film directed by Roger Donaldson, starring Robin Williams and Tim Robbins.

On the day of the big dealership car sale and the final day of OBriens deadline, the car dealership is taken hostage by an AK47toting motorcyclist Tim Robbins who believes his wife Annabella Sciorra is cheating on him. Joey manages to talk the man out of doing any harm to the other hostages, as police surround the dealership. Without realizing that the assailants gun is not loaded, the police wound him after most of the hostages have already been released which prompts Joey to promise to remain with him while he recovers. The crisis solves all of Joeys problems his mistresses learn of each other and dump him, his daughter returns, his job is secure, the Mafia don whose son was among the hostages forgives his debt, and he begins to reconcile with his exwife.

Source: Wikipedia