I went to the double black event in Seattle yesterday. I was great fun. They had a course set up with a 0-60 acceleration lane, slalom course, etc. I had the option of an 85D or a P85D. Gee, guess which one I drove! The tesla driver drove the course first just to show you the ropes, then I drove it and my wife also drove it. (It was a little slow so they let us both do it. It was Friday afternoon. They said Saturday was expected to be much busier.). We then drove 10 minutes or so on the roads, testing the TACC, speed limit notification, and other new features. Got some nice swag, sweatshirt, t-shirt, coffee mug for each of us.
For or some crazy reason I wasn't able to get anything specific about when the MX would be revealed, specifications, production dates.....nothing. (Not that I expected to, these folks don't know any more than we do.)
All in all, it was well worth the time. I would recommend it to anyone. I'm not exactly sure who gets invited. I received an email invitation. I thinks it's open to anyone who wants to register.