I'll throw in my two cents' worth, based on tuft testing before/after various mods.

As far as mixing apples and oranges, a lot of the posts here talk about airflow over 'the Fiero' as if bumperpads/aero nose/notchback/fastback have the same patterns. Get real.

The longer sail panels on the GT do help flow along the sides. I expected that flow on them would be over the edges and into the void behind the back window at least to some extent, but the video of my last tufted run shows flow going straight back.

Wing on/wing off/wing low/wing high is mostly a matter of taste, if most of your driving is below 70 mph. The jacked-up wing looks pretty rice but I like it, myself. And it has two advantages: visibility is greatly improved, since you're looking between the deck and the wing, and rather than flow over the top being turbulent or even reversed, flow is attached, so I assume there's less drag and actually some downforce generated, even if it's not Dodge Daytona height ( although my results are, I'm sure, influenced to some extent by the fact that I filled in the grooves on the bottom of the factory wing and taped them over).

And if you really want to improve flow over the deck on your GT, put in quarter window scoops.

The way to really tell what your wing is doing is to tie some ribbon streamers to it (no more than a foot long). Tie one in the middle, and one at each mounting post. Then drive at highway speeds and look through your rear view and observe them. Or have someone drive along side you and observe them. If the streamers fly backwards at an upward angle, then your wing is creating down force. If they flutter around and don't fly straight in any particular direction, then your wing is acting as a spoiler. That is, it is spoiling the airflow over the car. This doesn't create any down force as such, but it does remove any up force that would have occurred if the air flow over your car was smooth.

Just a note on this kind of experimenting in general - long streamers tend to get tangled up or fly all over the place. Tufts of yarn 2 to 3 inches long, scotchtaped down in rows, c. 4" on center, do a really good job of making local airflow visible. If they're curling and fluttering above the surface, flow is turbulent and not attached. If they're waving back and forth but lying flat to the surface, flow is likely turbulent but attached. If they're streaming straight back close to the surface, flow is laminar. Outside of a wind tunnel, tuft testing is the best way I know to see what's really happening as opposed to speculating about how the air might be flowing.

A perfect CF is .10 To get that number a car would have to be tear droped shaped. The back of the car would have to be tappered at a 10 deg angle, that would make a car undrivable as the tail would be too long.
Enginiers found they could make this tappered tail using air turbulence. You cut the end sharply and use a wing or spoiler to redirect some air flow producing a cone of turbulent air that follows the vehicle, this acts the same as if the cars body was tappered lowering the CF of the vehicle. The wing on a Fiero is disigned to do just that. Redirect air flow forward and backward to produce a turbulent area behind the rear window and a turbulent cone to the rear. It is this aerodynanic quality that makes the car handle better as the air flow around and behind the vehilce is less chaotic.

Rev.

[This message has been edited by the reverend (edited 07-09-2007).]