SDweller:
I car camp every year at the Portal. Motels in Lone Pine are waaaayyyy too pricey with very noisy traffic and teenagers on the streets yelling until it's time to get up and head up the mountain.
I have never seen anyone patrolling the lots. I put blankets over the windshield to keep out headlights of cars coming in late. Also hang up blankets in side windows. It muffles the loud noises in the lots. The lots are full of people until the store closes down. Around midnight hikers are moving and their headlamps will shoot right into your car and that's the end of sleeping.
But Please, please, please if you sleep in your car, for God's sake TURN OFF THE @#$%#$# CAR ALARM!!!!!!
Last year we were all sleeping good....for one hour and ONE MINUTE when someone sleeping in the car left the alarm on. Every time they turned over it went off! Myself and a lady sleeping in her car next to me got up at 1 AM, just gave up sleeping, and were on the trail by 2 AM. I did make it to the John Muir Junction at age 62 on one hour's sleep at 1 mph up, but my shoes ate my feet at that point. With a couple of hours more sleep, I could have made it (with better shoes.)