Got my Q8 4 months ago, 3 months old, and the dealer set me up on the system as a key user, but didn't pass on the key fob with the car ID.
By accident (!) I managed to delete myself, and couldn't add me back again. Called Audi support and with in 3 days, a short video call, they set me up again. No issues, just did the job, no charge. Brilliant!
And if you do get an Audi from a dealer, don't let them NOT give you the key user ID car code....