Hey there,
i asked the same question a few weeks back, and there was another before me some 6 months back, have a read of the thread below, and one of the posts also links to the other thread.
http://ecomodder.com/forum/showthrea...bad-20460.html
Lots of discussion, but the likely conclusion is that even if you improve the form and reduce drag, the increase in frontal area will probably offset this resulting in no net gain or possibly even a loss. I haven't burried the idea totally yet, but just put it aside for now as food for thought.