I'll add that the no moveable aerodynamic devices ruling has been applied very widely, and in sometimes surprising ways. The prime example is the ban on Renault's tuned mass damper from the 2005 time frame. It was a mass damper inside the nosecone, which meant that the moving masses were never exposed to the air outside the car. It was ruled that by influencing the movement of the front wing (maintaining it at a more optimal height), it was therefore a moveable aerodynamic device. The sad part of this story is that the regulators didn't actually understand what benefit the device was supposed to provide, which was to allow for a more compliant suspension (a non aerodynamic advantage), and in fact Mclaren had a suspension element, the interter, which did effectively the same thing, but was not banned.