Just hit the drive-in two nights ago. There is DEFINITELY tailgating before the feature.
They played 50's music on the FM channel until the movie started. I saw Star Wars IV (New Hope) and Jaws 1 as the double feature when I was a kid "back in the day". Didn't seem like a big deal then... :-)
I must say though, that with NATO involved, it all seems more serious. I never realized the geo-political implications of cinema in my car
PS: Paid $26 for a family of six to see Despicable Me 2 and Epic. Thats somewhere around 2 bucks per person per flick. I don't think the Warsaw Pact can beat that...