Hi EKSPCL,
my old bus had one of those fitted - see pic in My EK - it was purchased after the car - the old chap was given presents to adorn the car on birthdays and Christmas.
If it is the same as mine, you should find three self tapper holes in the A pillar concealed behind the door rubber - make sure you fill these - they are a cause for water getting into the dog-legs.
I left my tappers in the holes when I removed this visor - mine was called a "LowlLine" - or at least that was the manufactures name on it - think it was on the bracket on each side - mine has GTG - my faher "fashioned" a wind deflector for his caravan out of it....