it's a neat wing, but it will never "fly" with mainstream. people don't want efficient cars. they want fast powerful looking cars with moderate to low efficiency.
I'd be willing to bet that if gas rises to the $10/gallon level that it would be amazing to see the changes in what people want or will accept. The problem is that people don't want to change until it's already too late. This reminds me of a saying I heard growing up, "Dig the well before you need the water." It would be very difficult to dig the well while you are dying of thirst.
Horsepower is how hard you hit the wall, torque is how much of the wall you take with you.
After a bit more web surfing, I suspect that the errant tuft on the windscreen is a separation bubble. That might be something to try in addition to tuft testing - spraying some oil on the top of the car and seeing where it goes!
Which makes me think of turbulators. I have to wonder if the only reason that cars like the Lancer and the recent BMWs have those spikes that stick up (VGs) is that they are more easily accepted by consumers, and easier to wash without a bunch of sponge getting caught. I suspect something similar to what the sailplane people use might work better.
"And for something even more extreme, just look at the V6 Beetle RSi. Its huge rear spoiler and flow-directing upper window attachment are said to give 77kg of downforce at a massive 250 km/h - a pretty academic figure when that's apparently 25 km/h faster than the car can actually power itself to.... Drag also rises from the factory 0.39 to 0.40!"
All that downforce...so little extra drag.
I'd say a wing will help more than vgs would...cause I think you need something MAJOR to improve flow.
I think they work by creating a large defined high pressure flow that pulls the mixed air below...up into it...reducing drag from this lower pressure area.
I remember one ricer dude saying that his wing improved mpg...but not many would believe him.
Leading the perpetually ignorant and uninformed into the light of scientific knowledge. Did I really say that?
a new policy....I intend to ignore the nescient...a waste of time and energy.