Race with the Devil

"They witnessed an unspeakable act... it may cost them their lives!"

Race With the Devil is a 1975 Horror/road movie starring Peter Fonda and Warren Oates. Best buddies Roger and Frank, a pair of motorcycle mechanics and former dirt bike racers, set out on an RV trip from San Antonio to Aspen with their wives Kelly and Alice. It's barely a day into the trip, however, when they witness a Satanic cult sacrificing a young woman under the full moon. Now, the four are running for their lives as the cult chases them across Texas to silence them in a... race with the Devil!

Tropes:

 * B Movie
 * Bar Brawl: "There goes! First one of the night!"
 * Chairman of the Brawl: Used during the Bar Brawl.
 * Every Car Is a Pinto: One car blows up in midair when it goes over a bridge railing.
 * Evil Detecting Dog: Kelly's dog Ginger. It gets hanged from the RV's door by the cultists.
 * Getting Crap Past the Radar: The abundant nudity in the ritual scene. It's quite frankly amazing what qualified for a "PG" rating in The Seventies before the invention of "PG-13".
 * Hey You Haymaker: A variation. Roger calls out to one of the cultists on the roof of the RV, causing him to stand up and get creamed by the overpass.
 * Hollywood Satanism
 * Honor Before Reason: The reason why Frank doesn't turn around. He just wants to go to Aspen with his wife.
 * Human Sacrifice: And possibly a Virgin Sacrifice, too.
 * Mayincatec: According to the books Kelly and Alice steal from the library, the cultists are rooted in an ancient Aztec religion.
 * Molotov Cocktail: One of the cultists try use these against the protagonists during a chase scene, but after he falls off Roger takes the bottles and use them against the other cultists.
 * Police Are Useless: Sheriff Taylor and his deputies are in league with the cultists, and are covering up the crime.
 * Religion of Evil: The Satanic cult.
 * Reptiles Are Abhorrent: The cultists hide a pair of rattlesnakes inside the RV.
 * Screaming Woman: Kelly and Alice, unmitigatably so.
 * Secret Circle of Secrets
 * Stepford Smiler: The Hendersons, the couple that the heroes meet at the RV park.
 * Tempting Fate: "We don't need anything. We are self-contained, baby!" Turns out the RV isn't so invincible...
 * Town With a Dark Secret: The small town that the heroes arrive in after witnessing the sacrifice, and the RV park that they go to later.
 * Unintentional Period Piece: In an early scene, Frank is showing Roger all the features in his $36,000 RV (money that, today, would buy a bare-bones BMW 3-Series). Said features include a color television with stereo sound, a microwave oven, and tons of faux-wood and chrome paneling inside and out.
 * Town With a Dark Secret: The small town that the heroes arrive in after witnessing the sacrifice, and the RV park that they go to later.
 * Unintentional Period Piece: In an early scene, Frank is showing Roger all the features in his $36,000 RV (money that, today, would buy a bare-bones BMW 3-Series). Said features include a color television with stereo sound, a microwave oven, and tons of faux-wood and chrome paneling inside and out.