Yeah, especially the one in the middle. :D

They're not sharp and angular as Mitsu specified. They are soft and rounded. If they produce vortices, they will probably be weak and poorly formed. Too round and they just make turbulence, which is what the antenna base in the middle is doing. Plus the leading edge of the bar is acting like a stall strip, tripping the airflow right at the point you're trying to keep it attached. Might be a good application for VGs. Might not be a good implementation of VGs.

I wonder if these would help on the roof of my Dodge GrandCaravan?

I would be hesitant to call aircraft an alternate application. Last time I checked aircraft weren't designed to cruise down the highway at 70mph. But if I ever want to get my car to takeoff and cruise at 500mph and 35000 ft, I'll look at what airplanes are doing.

We only have one example but it's not necessarily a bad one. I wouldn't be surprised if WRC cars had them.

You have other cheaper options besides airtabs like airflow systems, $10 for 25ft strip:

https://www.gassavers.org/showpost.ph...4&postcount=36

That's for the adhesive. Their VG's are $6.35 to $7.95 a foot depending upon width, plus adhesive.

Darnit! I did not understand that.

So that means their cheapest is $3/foot and you still need glue and paint (it's purple!)...

Most of the aircraft in the world travel less than 200 mph and lots barely make 100 mph. Reducing drag on a car is a convenience. Reducing drag on an airplane is a necessity.

I suspect not. I'm going to try and sharpen the trailing edge of the roof of my Caravan like the Honda Odessy. Sort of a little kamback. It seems to be a recurring theme on a whole host of current model cars. I've debated retrofitting the aft wing that some Caravans come with, but can't find out if it is functional or decorative.

In back of vans/suvs, there's many popular styles nowadays:

- downward sloping spoiler (bmw x3)
- spoiler/wing with a hole (toyota hilander)
- camback (prius, but not 2-box suv)

https://www.analogstereo.com/images/om/bmw_x.jpg
https://www.hibredtoyotas.com/toyota-...-spoiler-2.jpg
https://image.automotive.com/f/miscel...yssey-left.jpg
https://www.familycar.com/roadtests/T...2/LeftRear.jpg
https://www.etendance.com/images/Peug...is%20Aster.jpg
https://upload.wikimedia.org/wikipedi...ce_black_r.jpg

Unclear what's better and how it plays with the rest of the underbody aero.