Is there any prohibition against sleeping in your car at Whitney Portal, or other nearby locations? I'd planned to camp overnight at the campground there before my Whitney day hike, but then I realized my station wagon has enough room in back for two people to sleep if I fold down the rear seats. That way I won't need a campsite, and won't have to mess around with striking the tent and packing things in the dark at 2:00 AM.

Assuming it's OK, how's the noise level in the parking lot in the middle of the night? Will I get any sleep there?