Only 1 car is allowed at the site. The rest of the cars need to be parked up front in the overflow lot.
A security person told someone on this group once that you can have 2 tents on the site or 1 tent and 1 camper on the site. However, I've had 3 tents on a site for 2 weeks and no one said a word or left me any nasty notes.
Having said that, you WILL need to make sure whatever you put up "fits" on your site. I would recommend you request Loop 2000 as they have the largest sand areas for setting up tent(s).