I think we need some more pics before we can tell you exactly how ugly that air dam is. :finger:
Seriously, you're not REALLY going to put that on your car, are you? It just looks way too plain and straight. You need at least some sort of lip on the bottom. And since the stock G20 has a big-ass grill in the center, i'd plan on cutting away a pretty good sized portion so that your radiator gets enough air.
BTW, what is that made of? Is it sheetmetal or fiberglass or what? And how are you doing to mold in the ducts that you're planning to make?