By golly it is on there... I don't think it should be
The Geo example given... is a good example of frontal area reduction and also better aero on the rear of the vehicle. I don't see a shred of evidence that the hood/windshield angle did anything good.
Look up aerohead's posts (he could very well be our best resident aero authority), in about 1/4 of them he states and restates that it is the rear end of the vehicle that benefits the most from aeromods.