Ok, figured out the Ford page, but haven't received a link via email that is required (says it may take 24 hrs):
first, join the Ford Audiobook group page:
https://www.goodreads.com/group/show...audiobook-club
Second, put the book in question onto your shelf:
https://www.goodreads.com/book/show/18774020-california
Third, THEN use the link above (the working one) to view the page that tells you that you need an email code:
https://www.goodreads.com/challenges/show/2668