Invasion Of The Saucer Men (1957)

Director: Edward L. Cahn
Writers: Robert J. Gurney Jr. (screenplay), Al Martin (screenplay), Paul W. Fairman (story "The Cosmic Frame")
Stars: Steven Terrell, Gloria Castillo, Frank Gorshin

Johnny Carter and Joan Hayden plan to elope but, first, visit a local Lover's Lane for a compatibility check-up.
Tooling along in the dark, with no headlights, they hit something, check it out and discover it is a little green man and scurry off to inform the local authorities.
The police think it is a practical joke but, when they check it out, they find a man's body there and charge the two with manslaughter. The victim actually had the misfortune to also run into some little green men, who came to earth in a flying saucer with bad intentions.
The two elopers escape from the police and eventually discover that a bright light can destroy the little green men, and they get all the swell kids in Lover's Lane to shine their car headlights on the little green men and this "Let There Be Light" crusade saves the world.
Released as a double-feature with "I Was a Teenage Werewolf."