I think a polycarbonate solution would be expensive and maybe even a bit too heavy...
I think a thin aluminum disk (not unlike the pie plates, except designed specifically for this) seems like it would be lighter weight and cheaper to make, and
if molded or pressed correctly, could possible just snap in to the existing wheel structure - with a release lever or bolt(s)
Could also look really awesome if designed just right.
Or uh, am I just re-inventing the hubcap ?
but in this case it's kind of a cap to go over a wheel not designed to otherwise take one...
On another note, I really think the moon wheels look cool - simple and retro.
If someone could design some aero wheels made out of carbon fiber that weren't too expensive and were specifically designed for the model S, well they'd have a real hit on their hands I think (especially if they were more immune to curb rash than the stock wheels.) Heck even just decent aluminum wheels.
I'm sure somebody will come up with some sooner or later -- maybe even Tesla.
