This animation from Mazda is quite interesting. I've been doing reading up on aero, looking to do some mods and found a video that was interesting.
First up note the grille area reduction.
Second (about 0:40), they demonstrate air swirling up over the wheel in the front wheel arch and imply that wheel well deflectors stop this to some extent. The accepted wisdom from my reading on ecomodder is that the deflector prevents air hitting the tire and making a high pressure area, but this points out that air would naturally flow up over/around the wheel to exit at the rear of the wheel arch.
Note the wheel deflector has a opening to let some air through!
I don't quite get the treatment of the A-pillar vortex though, is that just a smoothed out edge? They seem to imply they've wiped it out with a simple modification.
A little food for thought hopefully. Gives me a few ideas of what to do.