Ah, 99% of places. But was advised by hire company to avoid Phan Thiet, as they enforce it there, not sure how officially!

https://www.tigitmotorbikes.com/mui-...and-dune-trap/

Sorry, I should have said Mũi Né.

Incidentally, Tigit Motorcycles I can thoroughly recommend! Not the cheapest, but of ten bikes going HCM to Hanoi, not one broke down, all low mileage XR150's. The owner, Jon, is from Alton (UK).