I'd be careful with any online service that asks you for your reservation number, etc. and claims it can tell you where you are in line without any privileged/inside information from Tesla.
I only saw a conventional rearview mirror. Any news on a digital display setup so that you can still look out the back via a camera when the Vault is closed? Toyota has done this for years. Corvette has it, too. I'm sure other cars now have it.