This is beginning to reek of the McStay case, family of four who were found buried in shallow graves in the desert.
Someone set it up to look as if they drove to the border, parked their car, and walked into Mexico.
This location of Erin's disappearance isn't too far from where the McStays were found - Big Bear wasn't too far away.
I now see Big Bear isn't too far from the Marine base. I'm not suggesting the cases are connected, just that there may be a
purposeful intent for leaving Erin's car where it was found.
Now I'm beginning to wonder if she met a stranger or someone who works on base or even a ranch worker.
Whoever drove the McStay vehicle left it clean as far as we know. Wonder if Erin's car gave any clues for LE to go by.
I said very early on that my money was on a tweaker. While it isn't a big bet, that's still my guess.