Some things about this disappearance stand out for me
If you are taking the expressway from Brawley, you travel right through Coachella. So why was Audrey Moran going somewhere else to p/u Jon Reynoso (Darling)? Why didnt whoever was driving Jon drop him off at Audreys sisters house? That home couldn't have been too far out of the way.
There had to have been a meeting place planned. And maybe a separate meeting place was planned for a reason. Maybe there was a get together, Audrey didn't want to mention to her family for some reason. A house party... Since Audreys last ping is in East Coachella then she probably never left that area (of her own accord).
They are both missing, both have phones that are powered down around the same time, so the chances that they didnt get together seem slim.
So assuming all the above means anything (and isnt just random and unrelated speculation) my guess would be that Audrey went to pick Jon up at a residence, and it might be that there was a house party, or a gathering at the pick-up spot OR they went somewhere else, to someones home.
The way the SUV was left, and where it was left, seem more as if the driver wanted to get that vehicle away from the scene of whatever happened, and parked the vehicle where there was the least chance of surveillance and of being seen--low lit area, not well traveled at night...
They both strike me as very responsible and kind people. <modsnip>
And Audrey seems to have been helping get him around without complaint. So she's a great girlfriend. They appear to be very sweet, thoughtful people.
Wrong place, wrong time, probably. If something bad happened to these two, it could have been something as ridiculous as a fight at a house party that escalated and got out of control. But everything points to Coachella (and this city has had some issues with gang activity and crime). My bet is something went down there, or near to there.
(Where did Audrey live, by the way? With her parents?)
LE must not be in possession of their phones. If they had these, they might have been able to glean more info from them.