I'd like to see this product as well, but keeping the fog lights. There looks to be enough room on the passenger side to utilize the space next to the fog light for a vent. On the driver's side it may mean replacing the windshield washer reservoir with something smaller or a thick plastic bag instead of a rigid plastic container. There's just not much space back there.
I can imagine the price of a complete kit being pretty high though: new fog light bezels, ducts, new dust shields, hardware, (possibly a new windshield washer reservoir), etc. It's got to be difficult to figure out how to make a good product at a price the market will accept while still making a profit.