I thought I would install the fresh air cups that are cut into tne windshield. I changed my mind and it tripled the effort required because of having the fuel tank and instrument panels installed. Well I suppose that after nearly 10 years, what is a few more hours. I used Vans NACA vents and a swivel ball vent on the lower instrument panel...
Cutout opening.
Opening finished.
Pilots holes with the vent inside cabin installed.