You can contact your dealer to purchase one thru Ford Canada
Here are details as to the different packages http://fordcanadawarranty.ca/services/
I'm just looking at this myself now as well, pricing though is quite a bit higher than what I see others can get in the U.S...
He's actually has put a lot of effort into it, there is a website that was created a week ago and looks that it was registered by someone in Iceland... has 8 or so cars listed...
This one looks suspicious as well
https://terrehaute.craigslist.org/ctd/d/plymouth-2019-ford-mustang-shelby-gt350r/7401921041.html
I did contact them and there were enough signs for me to avoid it.....