Not so much weight concern, but the aero on it could definitely be improved. Would be nice if it actually covered the wiper blades, or at least sort of came up flush to them or didn't allow them to be completely exposed. Sort of surprised no one has this item. If you look at most track/races cars, this is usually a piece that is fabricated to make the hood and the front windshield flow a bit smoother. Sort of surprised that there is no post market option that is sort of in between full race car, and the OEM thing. Pretty common part for mustangs, American muscle, etc. a lot of trucks use them as well to help improve that area.
With the part not there, air actually travels into the engine bay, this is a good thing if you have one of those circular exposed air intakes like you see on old Camaros etc. for us it just slows us down so we want that whole area to be sealed off and allow no air in. The oem design basically accomplishes that, but leaves a lot to be desired-namely that 5 inch gap between the cowel, the edge of the hood, the wipers, and the windshield.
Something like this:
http://www.bing.com/images/search?q=...1WA&ajaxhist=0