FWIW, post USA my Mustang was next registered in NZ, later I brought it over to Australia.
In NZ it was issued with a new 17 digit VIN using the original factory VIN as a basis, and the new VIN plate was rivetted to the RH side of the firewall with two rivets.
The NZ VIN was used for importation to Qld and Qld rego. The original factory VIN is still visible on the LH apron and the door tag.
So it's visible if you look for it but not obtrusive.