Alfred Hitchcock Presents: One More Mile to Go (1957)

In the midst of a heated quarrel, a man lifts up the fireplace poker in his hand and brings it down on his wife, who drops to the floor. She's dead. The man puts her body in the trunk of his car and drives off, hoping to find somewhere to dispose of it. If he thought his wife was a nag, she'll seem like sweetness and light compared to a motorcycle cop, who stops him and insists he fix his broken taillight.