Supernatural - Roadkill Season 2 Episode 16

Sam and Dean encounter a woman, Molly, who is being chased by a farmer down the highway. Upon further investigation, the brothers learn that Molly and her husband were driving down the highway when they saw the farmer standing in the middle of the road. They swerved to miss the farmer and the car rammed into a tree. When Molly came to, her husband was no longer in the car with her.