I remember seeing a parade in Saigon. It was to celebrate National Day; was that 3rd November? Around then in any case. It celebrated the overthrow of President Diem. I am not sure of the date and won't look because it was not a good reason for a National Day which should celebrate something momentous in a country's past and not just one of numerous coup d'états.
Thieu was not applauded at the parade. There was no popular support when he appeared. Frankly it was rather embarrassing, but perhaps he was used to it.
From time to time they would fill a sports stadium up with schoolchildren who had no choice but to applaud. What I remember from the parade are two things. One was a very gung ho commander of a Ranger battalion. This was rather unusual and to be noted. I rarely saw keen soldiers. Most were war weary. The allied troops had small detachments at the end of the marching units. This was to show the Vietnamisation of the conflict. That is to say that the army of South Vietnam was now taking over a bigger share of the conflict. The second thing I remember was seeing kilted Australian pipers bringing up the rear. Mind you, I always feel the pipes and drums should always lead a parade, but then having served with the Black Watch I'm prejudiced.