I don't think the Vietnamese American will buy those cars.
They still think all successful business in Vietnam has some ties with the regime (which they hate a lot).
This business is even more problematic to them since the owner is a Northerner, he had started on Eastern Europe, and his father was a military officer.
Know a lot of Vietnamese folks around the Washington DC area. Like the Cubans, most of the Vietnamese in the US are here because the NVA military cause them to flee. A lot of them vote Republican and probably aren't crazy about a former NVA officer selling them anything.
There are 2.2 million+ Vietnamese Americans so maybe some of those will buy on principle.