Drive-In Scene
The movie trailer that is showing during the Drive-In scene is not Blood Bath (1966) as listed in references, but actually Joel (Bloodsucking Freaks) Reed's Bloodbath(1976)paired with a re-named giallo called Blood Feast as a double feature. I recognized scenes from The Red Queen Kills Seven Times, and I had heard that film had Blood Feast as an alternate title, but I couldn't find any references to it. Apparently Cannon renamed the giallo to make a "bloody" double feature.
I couldn't find a video of the trailer, but I did find an ad.
http://www.critcononline.com/images/blood%20feast-blood%20bath%20ad%20mat.jpg
Now I feel like a nerd. ;)