First, I just want to say: Don't worry, I'm not here to beg for your camping spot. Me and my 2 friends have come to accept that we're not going to be camping comfortably due to our procrastination.
Instead, I want to ask what other people have done in this situation. All other camping spots (Lake Cahuilla, etc.) all seem to be fully reserved so it doesn't seem like that's an option. I've heard that their is a Walmart nearby that allows 24 hour parking. Is this a good alternative? What do you suggest for showers? Will the desert heat turn our car into a toaster and burn us alive? Any and all advice will be greatly appreciated. Thanks.