Chains (1989)

We leave no traces, but we live in memory and in the nightmares of our enemies.

On their way to a Chicago jazz club, two very white couples take their luxury sedan on a wrong turn into hostile gangland territory. They accidentally witness the assassination of the scrawny punk kingpin of local heavies The Chains. No sooner does his ventilated blond spiked noggin hit the concrete than The Chains are up in arms and looking for any possible suspects. As the yuppies try to peel out to safety, a frenzied youth spazzes his way into their unlocked back door with a resounding "Get me the fuck outta here!" It turns out the new passenger is indeed the hunted gunman, though he was only avenging the murder of his baby brother.