We still have a Drive-In in our area and it's packed every weekend, they even have decent food. They show first run films, usually family friendly, except for the all night horror specials! We usually stop & get a picnic supper on the way and enjoy it before the movie. We still sneak beer in.
I can relate to the wearing your Pajamas to the drive in, my parents just put us all in the back of the stationwagon and we'd be off.I can also relate to the steamy windows!