here the last few days about spats, deflectors and such and it seems the problem to overcome, or at least reduce the effect of is the bow wave.
It would seem an easy fix with just a horizontal splitter mounted at the bottom of the front fender. Then you might reduce the 60 degree airflow deal at the bottom front of the car, and actually be able to use deflectors directly ahead of the front tires.
http://wiki.seloc.org/a/Image:Splitter.jpg
What say ye?