[aerohead]

I don't have the work with me,but FIAT investigated nose drag,and the tuck-under nose as you have has the highest drag.
A vertical,or slightly slant-back nose are equal as far as drag reduction compared to the tuck-under.
I chose the slant-back, as it best imitates the half-body and also channels air to the sides a bit like a splitter.
I found some gray urethane rubber floor mat for the lowest portion at BIG-LOTS.$16 for 16-sq-ft.If I hit a curb parking,it just deforms,then springs back when backing away.
Last night,coming in from West Texas,I pulled 35.26 mpg at 60-mph.This is without:headlight covers,belly pan,or any boat tail.
And I attribute the good numbers to the airdam portion of the nose.I've never seen numbers like this without it.