[Big Dave]

Myair dam has a curve in it against the wind plus two flat aluminum plates to hold its shape. It holds its shape well at road speeds.

As for grille blocking, you can fearlessly block off the vertcal openings - they are 100% decorative. You could block 6 inches off either side of the horizontal opening as well and still get full air flow to the condensor, intercooler, radiator stack. My chin slot also gives air flow to the tranny cooler.