[Hermie]

I ordered a set of the delta-shaped "Vortekz" generators thinking that it would smooth airflow on my back end, but after some tuft testing, it showed something I wasn't expecting at all.

I don't have a camera for pictures, but airflow was attached down the middle of the window all the way to the base, where the airflow apparently strikes the trunk surface fairly hard and causes it to move towards the sides of the trunk. Behind that, airflow looks smooth rearward.

On the sides of the window, I noticed rotational movement of the tufts giving the impression of airplane-style swirls off of the tail end. From standing behind the car and looking at the passenger's side of the rear window, the air rotates in a counter-clockwise half-circle on the glass, and it looks like it'll make a full swirl off of the car.

So, has anyone else observed this, or know if that's a detriment to drag?