None were used ,officialy, in Viet Nam. They were tested in Thiland. But the test vehicles were not close to the vehicles we have. They were lighter and were powered by an air-cooled Chevrolet four cyl. (Corvair)
You'll hear a lot of weird stories of where they were used but ,no. Most went to Germany and England. Many were sold to Mexico and Spain after they were s---canned by the Army. The Guard had some that were used up into the 80's as did the Marines. Suposedly, the Marines had the last one they had in the first gulf war.