[jime57]

I have been avidly following the interesting thread on boattail extensions for the Insight 1 now active in another thread here. Not to highjack that thread, I'll just ask a question that has been puzzeling me.

Is there a role for a defuser of some sort for the underneath of boattail extensions? I know that there is lots of concern about how the air underneat flows, and it influences, in most minds, the maximum departure angle of the underside.

I'm a Formula 1 fan and I recall how the introduction of an innovative rear diffuser in 2009 by the Brawn team gave them a significant aerodynamic advantage. It is true of course that the speeds are dramatically different.

I also see some "funny little things" going on on the rear of the stock Insight 1and the Prius that cause me to wonder. The Insight 1 has an undercut section on the bottom of the rear bumper which I'm guessing is aero driven. The Prius uses strakes(right word?) behind the rear wheels to form a sort of channel for air exiting the rear underneath.

Just thought I'd ask. I'm still pretty much a neophyte at the aero stuff and want to get Hucho's book soon as I can get $100 tegether.