Just as a heads up to my fellow Coachella-ites:
A co worker of mine went to the phish festival in october that they had at the polo fields (for those who dont know, that is when they tested the car camping idea, and since it worked well they decided to use it for coachella) and he was talking to me about the security involved.
Apparently, they are pretty fuckin thorough on the car searches, he said he had packed his truck from the cab to the tailgate (with a camper shell) and had a few bottles of tequila stashed all the way in the front behind everything else. Upon pulling up, they made him unload his entire truck load and lay it out on the grass, then searched all his coolers and bags, even the inside of the cab. They found his stash, poured out all of his bottles (Patron!) and confiscated the bottles. They also confiscated a pipe from him and gave him a "warning" after he "tipped" them $20.
So, just a word of warning, hide your goodies well! They are going to be nazis about your car.