Just received a V1 few months ago.
I've been driving for more than 20 years. The police here are putting up too many speed camera recently and I need to feel more confident driving (not to speeding purposedly).
RD is not forbidden from using in Vietnam but it is prohibited from importing. My V1 cost me 600$ cause I bought from V1 and shipped to a friend in LA and he has to pay smbdy to hand carry to me.
My V1 have saved me about 5 times already.