Visas and border crossings forum

Hi guys, can i please get some advice for a trip i will be performing very soon.

Me and a friend are planning on flying into Vietnam, purchasing a motorbike, and proceeding to ride for 3 months. We will be crossing the borders into Cambodia, Laos, Thailand.

now. we understand that it is actually not legal for a tourist to purchase a motorbike in Vietnam, but the authorities turn a blind eye, is this correct?

but everyone gets away with it, so im not to worried about that. what i cant find information on is how easy it is to take the same bike across all borders. has anyone done this? i am planning on getting a bike and obtaining ownership papers etc, will this suffice?

any information is much appreciated. We are Aussies if that makes any difference, and have already sussed out visas etc.