Road-Kill U.S.A. (1994)

Hitchhiking college student Josh Overcash is about to accept a ride that will change his life... into a murderous nightmare. His new traveling partners, Clint and Marla, are a pair of serial killers who travel hidden back roads, stay in the sleaziest motels, and maliciously murder anyone that gets in their way. The thrill of the kill is their way of life and they want Josh to join in the fun of traveling and killing.