Maybe it's because I live in a big city, with a fairly high crime rate to go with it, but very little is off the table for me in regards to theories (within scientific reason, that is) about how his car ended up on Salt Flat Road.
Several years ago my own brother was carjacked downtown. He was leaving his place of business during broad daylight, when he was accosted by another man, at his driver door, just as my brother got in to his car. He showed a knife to my brother and said "drive me to the hospital" (about one mile away) my brother told him to hop in, and my brother drove him there. The carjacker then showed the knife again, demanded my brothers wallet, brother complied, carjacker hopped out, and away he went.
DB called LE, gave a report. No one was ever detained. Yes, brother was safe. He did exactly what carjacker asked him to do, and he went on his way. If my DB hadn't cooperated, it could have turned out much differently. He easily could have been injured or killed during a confrontation, his body hidden, and his car left behind to be found later.