Has anyone installed a permanent defroster system on their boat? I don't really like having a couple of fans up on the dash because they impair vision and my dash always has lots of other crap on it. What I envision is a small squirrel cage above the electronics shelf with directable vents (like you have in a car) coming through the plywood. The ductwork from the fan to the vents probably won't be pretty but won't be visible. Does anyone have any other ideas for a permanent defroster?