Come early if you want a good spot. Not saying there are many bad spots but it really depends on what type of vehicle you will be in. We drove a car so we had to park a few rows back but close enough for a good view. You also don't want to be finding a spot once they have the lights off and your headlights our in other people's cars.
Great deal at $9 for a double feature. You can always check the website to see what the shows are (www.autoramadrivein.com). Concession stand offers a nice selection at fair prices too.
No outside food is permitted but they weren't peeking into our car or anything. The only real issue is the time it takes to leave if you stay until the end which is understandable with every vehicle exiting through a single lane.
My advice is come early with a couple fold up chairs, grab some snacks, and enjoy a nice calm evening of good company and entertainment.