They get 700-800 cars in during the evening. It's a huge event. I think it starts at 2pm and is usually only $1 to show your car.
http://maps.google.com/maps/place?hl=en ... 6117177654
It's the only show I regularly attend. Wear a hat and sun block, there is not much shade in the field. And get your burger early before the line wraps around the building.
Tim.