"As to the skirt issue, I bet it's down to cost vs gains. Is it worth the money and time to design and create a removable panel for the minute gains that could be made up with smarter driving?"
Smarter driving? Oh,
azraelswrd, you crack me up!
I still think skirts are a factory accessory that would sell if they can show real MPG gains ... look at all the pour-in nonsense that is sold for engine sumps and gas tanks? How about doo-dads like the Tornado valve? Most of this doesn't work ... but it sells.
Show a gizmo people can purchase and stick on their cars (in this instance, a set of skirts) and people will buy it.
The downside is that a different set of skirts has to be designed for each vehicle ... pour in goo is a one-size-fits all product.
