Cornell - wanted to share a quite similar experience:
Ordered S75D on Oct 11th, with estd. delivery late december (was also told the date would slip if I ordered after Oct 12th). Logging into mytesla.com even today still states "your tesla is scheduled for production", no delivery date anymore, no VIN (almost 1 month 1/2 after order confirmation), just a RN.
I was then told by our local store manager 10 days ago the car had not entered production, that some communication has messed up after the sales phase... They would look into the matter (and appreciate my feedback to increase service quality etc etc) but after almost two weeks of talking face to face to him, still radio silence, and no updates on mytesla.com page (still "scheduled for production"). E-mails are either not answered at all or after more than a week. I find it disappointing the lack of accurate of information and responsiveness from such a high-end "niche" product company.