Flow through ventilation

[EJ_Dave]

Has anyone ever modified an early Holden to a flow through ventilation system or know how you would do it? It seems that cars with flow through ventilation (eg HQ and later Holdens) are much less prone to fogging (a major issue in Canberra winters) even without air conditioning. I have an original EJ/EH heater/demister in my car (EJ) but I often need to open the quarter window as well which sort of defeats the purpose of having a heater.

David