What are we missing, what should I make on a VMC?

[gideon]

Also thinking of aluminum defrost grills, no more warping in the sun.

The defrost grill sounds like a nice option.  If you do that, try to design something that can be installed and removed with the windscreen in place.   I think they should be black anodized, so you'll want to do a batch of them for anodizing.