You can't hold a good engineer down. In spite of the increasingly tight limits imposed by F1 technical regulations, the innovations continue to appear. Latest is McLaren's extension to the wheel covers that are spreading through the paddock this year.
McLaren MP4/23
I gave my opinion on the legality of the wheel covers in my post entitled Wheel Fairings and the FIA (and an interesting technical discussion resulted in the comments system), so I will not rehash the argument now. McLaren's development of the idea brings me back to the subject, however, and I am forced to ask, "Just what are they trying to achieve with this ugly addition?"
My first thought was a return to the brake cooling excuse employed by Ferrari to gain acceptance from the FIA scrutineers. That bit sticking forward from the cover could be a scoop intended to draw air in behind the insert and so cool the brakes. This function is already performed by scoops inside the wheel, however, and close inspection of the photographs available seems to indicate that it is too flat to contain a scoop.
Since the leading edge of the extension curves around to follow the shape of the tire at the front, the inevitable conclusion is that it is designed to conduct the airflow smoothly around the outside of the wheel. This would confirm that the primary intended function of the front inserts is aerodynamic; filling in the wheel well has the immediate effect of decreasing the vortices created by a wheel turning in the airstream and covering the tire in front of the well assists in this.
In fact, if one could extend the wheel insert so that it covers the outer sides of the tire completely, the reduction in drag through turbulence would be a big improvement in the overall aerodynamics of the car. Perhaps McLaren are working their way to this in small steps, hoping that the FIA will not ban it.
Whatever the reason given for the covers, they are a good example of how the spirit of the rules can be circumvented by stealth. Originally introduced by Ferrari on the rear wheels as assistance in brake cooling, the inserts have spread to the front and become static. Now they threaten to grow beyond any pretence at brake cooling.
Racecar Engineering had a novel explanation for the original introduction of the covers; this involved linking it with the "secret gas" so famously used by Ferrari to decrease graining in the tires. I found the reasoning dubious at best and irrelevant anyway once the innovation had spread to the front wheels.
Presumably, the FIA feel they cannot rule out the covers, having allowed them in the first place, but I would be surprised if they are not at least a little uneasy at the way in which they are being developed. It becomes clear that the front inserts needed to be static because their primary function is aerodynamic - if they moved, they could be banned immediately as movable aerodynamic devices. With the growth of the inserts to threaten covering the whole wheel, it might be necessary to go right back to the fifties and the ban on covered wheels to find an excuse to outlaw the things.
And they do need to be declared illegal. The expense and effort required for their development is illustrated by the fact that the poorer teams do not have them yet. How logical is it to allow such expensive modifications while claiming a desire to keep costs down? The inserts contravene the spirit, not only of the regulations, but also of F1 itself - hence the need to go as far back as the roots of the sport to find out why they look and feel so wrong. If the covered wheel is anathema to F1, then any new way found of covering them is still contrary to the original concept of the sport.
I say ban the horrible things before they can get any uglier.