... if he pays w. certified check or MO its as good as
cash..
Wrong, big market in stolen/forged bank checks and money orders.  Plus
he may ask later that you accept a check for more than purchase price,
deposit it and give him cash for the excess amount.
On the other side, this guy could have a good market for these vehicles
'at home', wherever that is, and is trying to buy anything he can get
and ship it back.
Caution is the word.