[MetroMPG]

I was actually thinking of a tight form fitting closed cell poly "pool noodle" to fill the fender gap. Plus moonies.

I'd only radius the aft portion of the wheel arch with half a noodle. I'd extend the front/top surfaces out flat toward the tire. Probably minimal gains on an Insight though - they paid attention to the wheel arches in their design. (I'm assuming you drive an Insight from your username.)

The threads in question:

http://ecomodder.com/forum/showthrea...-0-a-5462.html

and

http://ecomodder.com/forum/showthrea...light=skirt%2A