I did the drive in a few weeks ago. We go about 30 mins before hand so we can go to the bathroom, get snacks, etc. We sat in the car but many others brought lawn chairs. There were a number of kids running around catching lightning bugs but I would suggest bringing something for the kids to play with in the car in case getting out and running around isn’t an option.
Also, Aiden fell asleep about 15 mins into the movie… :/