that the water was not moving or evaporating in the middle of my rear window. i have a picture of it in my garage and marked the area in black. if i understand aerodynamics correctly. shouldn't it be even in the back with the wind pushing it down or evaporation,etc..?? and it always has the swirl look to it. like hurricane shape. so what is excately wrong here or is there something wrong with the aeros of the car? there are no aero mods in the front, but it does have a OEM spoiler on it.
"But Doc, we dont' have enough road to get it up to 88 miles per hour"
Looks about the same as mine. The rear window is too steep, and the airflow detaches from it. Hopefully your spoiler is in the right place to catch the attached flow, otherwise you have a huge trailing wake. It's a design compromise between rear seat headroom and airflow, and in our cases, headroom won. Look at a Prius to see the right way to do it.
I had the same condition, then I replaced the seal to stop the leak onto the inside of the window....
The detachment of the laminar flow might not be a bad thing. The Kamm design principle takes steps to produce this delamination, but the glass is nearly perpendicular to the air stream, not nearly parallel to it. It seems that either extreme of angle is acceptable, but there is some relative orientation between these extremes that is not.
John Cobb's land speed record Railton - Mobil Special was regarded as close to an ideally teardrop shaped speed vehicle. It was about 9 metres (28 - 29 ft) long; most of the back half was the fast back, the pointy tail. This is too long to be practical added to a road vehicle. The Kamm tail it seems. perhaps tries to keep the delamination, the angle of separation, minimized, whilst hoping that the disturbed, low pressure air zone behind the vehicle will assume the shape of a pointy tail.
A spoiler on top of a Kamm - like tail is often seen, what this may do is to prevent the laminar/turbulent flow boundary dipping too sharply, which could put some laminar flow in to the low pressure zone. That might increase drag: hence a spoiler, not so much to reduce drag, but prevent more of it occurring.
You're pretty much always gonna have a stagnant spot right in the middle of a rear surface, but I guess that should be happening lower down, not on the window.
I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice