Two Thousand Maniacs! (1964) on Netflix

Over the opening credits, six Yankee tourists whom make up two married couples, John and Bea Miller, David and Beverly Wells, driving a white Cadillac convertible, plus an unmarried couple of Tom White and Terry Adams, driving a red convertible, are lured via detour signs placed in the road into the fictional small Southern town of Pleasant Valley by "redneck" citizens, to be the "guests of honor" for the April 1965 centennial celebration of the two days where Union troops destroyed the town at the end of the Civil War. The three couples meet the town mayor, Joseph Buckman, and his two right-hand men, Rufus and Lester (the men who placed the phony detour signs), as well as shop owner Harper and his girlfriend Betsy. The tourists are initially treated with hospitality and given rooms to stay in the local Hunter Arms hotel.