Agreed, the mesh on the side scoops is finer (i.e. blocks more airflow) than those on the radiator and hatch...I'd seriously consider putting a duct on the drivers side c pillar and see if that helps. I think it would look pretty cool. You can't see both side of the car at the same time so whycare about symetry
Frank found that the mesh blocks a heck of lot of air on those side scoops, so I would certainly remove that jazz...
The reality is that you need a lot more air to really get some good efficiency out of those ICs and I think you've shown that the big issue is that little opening. If you can double the size of that hole, you'll probably double the air... If I were you, I'd start doubling
Also, and not surprisingly... the flow through the intercooler seems proportional to the smallest cross section in the ductwork... so doubling would be good...