I'm not sure whether this will help or not. But when our Roadster was a couple of months old, it had an intermittent problem where, when parked, it would just start spewing apparently random error messages. And, of course, not go anywhere. We had it picked up, and interestingly they pushed it out of the garage and then drove it onto the truck! It seemed fine. But the logs had all these weird error messages. Anyway they did all sorts of stuff to it, including a new PEM, and returned it after about two weeks, just in time for an Earth Day display at work. Unfortunately about a week later the problem recurred. It took about three weeks this time (BTW, that *does* make it a lemon under CA lemon law). It turned out that a wiring harness over the back axle had either broken or not been done right in the first place, and the wiring could fall onto the axle, which wore off some of the insulation. When moving there was generally no problem, but if parked, and things happened just the wrong way, it shorted the CANBUS and caused the problem. Tesla shipped two of the engineers down to Santa Monica, and I gather told them not to come back until it was fixed.
I was of course very disheartened at the time. But (and here's the point of the story), (a) Tesla WILL take care of you, and (b) when it comes back you'll fall in love all over again.
So buck up. And if you're in San Diego contact me and I'll lend you the roadster, but I gather you're not, and it isn't an open invitation for anyone.