MIDDLE RIVER, Md.—On a moon-filled Saturday night, D. Edward Vogel stood in the projection room of Bengies Drive-In Theatre, surveying a field of cars that turned out for a chilly November triple feature.

“How many think we should return ‘Bohemian Rhapsody’ next week? Flash your headlights,” Mr. Vogel said over the sound system during an intermission. Several cars did.

The...