Remember, even if the New Beetle has attached flow, that is not the goal. I will posit that the sharp edges on the NB only generate very large vortexes in the wake. Since the air coming off the side will detach at the top first, the vortexes will rotate inward to the centerline, perhaps pushing that air down to an "attached" state. This would make it appear that the car has good aero, but in fact doesn't. I think only a wind tunnel test would show us for sure.
We really can't tell what's going on here but it does not look like the air is going straight down the rear window. Look at how the tufts are pointed toward the centerline.
I don't know any of this- it's all theory. But with everything I've learned on this site it seems very unlikely that the attached flow on the rear of a New Beetle is "healthy" attached flow.
The Type 1 has similar results
I'm not sure what to make of this. If you say it's all attached flow you've got to tell me why the New Beetle and not a Corolla sedan's rear window with the same angle.
I'm not trying to put you down or crap on your ideas; I'm just telling you the problems I see, and why I think that.
