It'll be April or May next year before we go away anywhere
However this weekend I put stabil in the gas and ran the engine for 5 minutes, while it was running I turned the defrosters on full and both curtains were 3 or 4 inches off the dash in those areas, so I imagine all will be well.
As for making and selling more of these, I will have to price up time & materials, 3/16" machined aluminum, sandblasted then clear lacquered. The perforated steel mesh is just painted black.
I'll have to see how many I can make in my spare time. Mel