Ah... I found the answer here: http://www.coachella.com/visiting-th...-site-camping/
Looks like I will need to leave the car in the spot if I want to keep the tent set up there.
May I drive in/out of car camping?
Once you are parked in a camping area you may not move your vehicle for the duration of the festival. This is for your safety and the safety of your neighbors. However, if you need to leave early, please let security know, so they can help direct you out safely. Your car will NOT be admitted back in to the car camping area once it drives out. Given the configuration and the limitations of our site we need everyone to cooperate with the staff and park where directed and remain there. This is the only way that we can accommodate all ticket holders on the property. Please understand that when anyone disregards the parking and camping instructions it creates havoc that will ultimately impact everyone’s comfort and safety.