It all began in Camden, New Jersey when a local businessman took the idea from his mother. Richard Hollingshead's mother complained she did not think the seats in the movie theater were designed for all sizes of people. She told her son it was a shame you could not sit comfortably in your own car and watch a movie.

With that idea in mind, Richard utilized a white wall of his auto parts machine shop to show a movie using a 16 millimeter projector along what would become Admiral Wilson Boulevard. He eventually built a new "Park-In" movie that opened on June 7, 1933, for $60,000. Six-hundred cars attended opening night. The first movie shown was "Wife Beware" starring Adolph Menjou.

from a Daily Iowegian article, courtesy of The American Roadside.