My wheel dams are not 90* to the road they are angled back at the bottom I will think about cutting them down or completely removing them. they only stick down just about .5 inch below the air dam. On that note I am rolling around the idea of a front splitter that would create a true flat front tray. As the car is now the air dam bottom is even with the bottom of the engine sump.
the back of the car has been cleaned up a bit with the removal of the roof rack and some ineffective VG's. the car is also designed with a taper front to back both top and sides. I may consider one or two things to create more of a virtual boat tail.
BTW refer to the flow illustrator it gives the indication that the car creates a virtual boat tail. I am aware that it is more of a guess than anything else but it is encouraging.