@mcrews, just checked out your grill block and belly pan threads.
I'm pretty sure I want to do a Belly Pan like the R8 but I'd ideally like to have it metal and with metal mounts. I'll look and see if I can find something like that already pre-made. If not, a couple people in my family are much better welders/have better access to welders/lifts and they can help me out. Found something I could prebuy, install straight in with some brackets, however the way it covers the bottom of the car doesn't allow all the gaps to be filled in. Jetta is pretty smoothed out in most placed except the front.
http://forums.tdiclub.com/showthread.php?t=299009
As for the grill block, I was debating about blocking out the upper grill, but your stealth concept gave me the idea of potentially blocking out with plexi glass. Don't know if that's possible, but we'll see.