Video of Nismo wing aero testing

InnerDragon10

It may be. That design straightens out the turbulent airflow traveling over the top of the car (and in the boundary layer) using the vertical fins. The clearance between the glass and spoiler probably forces air between it and the glass, smoothing out any small vortices or eddy currents sticking to the surface of the car. Beneficial? probably, but not at conventional speeds..
The solution?
Drive unconventionally fast No seriously though, diffusers that small probably don't affect something the size of a car. Looking at F1 cars, the diffusers in the back are significant in size relative to the car and have proven to be effective at reducing drag.

(If anyone was wondering, I'm a mechanical engineer. I don't claim to know exactly what I'm talking about because I don't work around aerodynamics, but it was my favorite course in college and I remember some stuff from it lol)

I'm not quite sure if it violates forum rules (I read them) so I apologize in advance, but car and driver has a great article about diffusers and aerodynamics under a car. The idea can be made to help understand air movement over a car.
(again, sorry if this isn't allowed please don't ban me; just slap on the wrist?!)
http://www.caranddriver.com/features...y-suck-feature