Cd, perhaps you meant to provide this link?:
AutoblogGreen
(doh, you were busy posting the photos)
The fact that this Fusion measured at 0.20 tells me that the same simple collection of aero mods should have great benefit on a Jetta also.
That is actually exactly what I am planning for my own VW Jetta. I hope to get it built this holiday season. But I'll start my own thread for discussion so as not to hi-jack this one.
p.s. I plan on mounting VGs on the roof, just for fun.