My wife has had several incidences of getting in her now 3 1/2 week old Model X (maybe 6 incidences) where she clearly had the key and the car opened as usual for her, but when she attempted to start the car she got a key not found error message on the dash display and the car would not start. She was able to start each time using the app. Most of the time the car works as expected. I had this occur yesterday in my Model S, but it self cleared after a few seconds and I did not have to resort to using the app. A few thoughts... is this a one off issue and we need a new antenna or something? Has it happened for anyone else--the sales person in KC that I'm speaking with says it's not a known/widespread issue, but our DS admitted that it had occurred to him once a week or so ago in a different vehicle. The only other thought I had was to wonder if the fact that we have 2 different Tesla Fobs on our key chains at the same time is if there could be some interference from that...maybe the car is picking up the Model S fob and not recognizing it instead of finding the Model x fob? I don't know enough about how the fobs work with the car to know if that is plausible. The sales guy is coming on Monday to orient my wife to the vehicle and "is going to see what he can find", but I'm not optimistic that he is going to be capable of troubleshooting a nuanced intermittent issue like this. We'll probably end up with a Ranger visit in the near future, not in a rush as it's not that troubling.