It was Beach and 20th street. You can Google Midway City Sanitary District and see a map of the city. Most people have never heard of it, it was a tiny place. The drive in you may be thinking about may have been the HWY 39 near Beach and Garden Grove Blvd. Are you thinking of the "Rollertorium" in Buena Park? It was on the Northwest corner of Stanton Ave and Commonwealth (I think).
Beach and Bolsa. The Westminster Cemetery was on the Nothwest corner area. The north edge was almost to 17th Street (Westminster Blvd now) South edge was McFadden.
Thanks to everyone. Hey it was the 60's. Those truly were the days I do remember the 39 drive in. I remember my first date after getting home from Vietnam was seeing a movie there. I don't remember the movie. I think it was either The Graduate or Rosemary's Baby. There were a lot of drive in movie theaters in those days.