Sheila and the Brainstem (1989)

Plot

In the American Southwest, Taz—an eccentric dreamer—has briefly lost track of the shriveled, ancient Brainstem he discovered in a strange underground realm, convinced it holds the secret to eternal life. Three rebellious punks, Sean, Head, and Billy Dork, swipe it during a convenience-store holdup, mistaking it for beef jerky. Newlyweds Bruce and Sheila accidentally walk into the clash between Taz and the punks. The punks seize Sheila as a hostage, and Taz grabs Bruce as his own; thus begins a bizarre chase. The two sides tear across a landscape of identical convenience stores, cookie-cutter housing developments, and runaway consumerism.