Hi guys,
Maybe you are interested in some aero tests done to mirrors
check here -->
http://www.racemirrors.com/engineering.html
The idea is using an aerodynamic shape but also to add a
clear attachment to the mirror, in order to reduce back area (as kammback does)
I think this attachment must reduce Cd in all mirrors, and also it is good for DIY and it may be done in many cases
Worth trying?
Cheers,
Mrk