Hi David,
I don't have my invitation yet. I live in Canada and I have an Amazon.com account and an Amazon.ca account (the .ca account is largely unused due to the high prices on it and lack of things like Echo Auto). I just looked at my Amazon Alexa app and devices and when I pressed Amazon Echo under "What type of device are you setting up?", the Echo Auto came up as a choice. I wonder why it isn't coming up for you since you obviously have the Amazon.com account. All my devices are registered on Amazon.com versus .ca. Perhaps yours aren't registered on .com?