Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
"If you're going to race with the Devil, you've got to be as Fast As Hell!"
"Peter Fonda and Warren Oates are burning their bridges and a lot of rubber... on the deadliest stretch of road in the country!"
In a motor home interior scene full of tension and terror (as long as you don't know anything about snakes) a woman goes to make coffee and finds a couple of rattlesnakes (western diamond-back rattlesnakes) in the cupboard. They were put in there by the demonic cult members who have been following the motor home drivers across Texas. The snakes leap out of the cupboard as if they were spring loaded (like all snakes do in movies) terrifying two screaming women and two men who wrestle with the snakes forever trying to kill them with a ski pole. Peter Fonda grabs one by the neck and whips it to death then the guys toss the snakes out the trailer door.
The rattlesnakes we see in the movie are real ones. I read somewhere that the actors are actually handling live rattlesnakes that were "milked" of their venom, making them less dangerous, but still potentially deadly. I suspect that someone either surgically removed their venom glands or sewed the snakes' mouths closed, or both.