Ooo! A tail treatment? Excellent. I have the impression that Prius owners seem to be afraid of doing that. (Cough, cough Daox cough.)
Other than this guy, who posted the tail for sale and then failed to answer replies and PM's:
http://ecomodder.com/forum/showthrea...mpg-24999.html
So is your MPG going up? I'd think with dual mirror delete and smooth wheels, that would be detectable.