I have an observation regarding the rear spoiler / down force issue. Before I say this, let me qualify it by saying I am not a mathematician, but I do enjoy fig newtons.

Yesterday I found myself at the car wash without having brought my detail kit with me. I live very near the George Bush (boo!) Tollway in Dallas, so my plan was to clean the car, leave it wet, and "air dry" it by driving 90 mph for an extended period of time. We've all done it, so please don't send me a link for microfiber towels!

Anyway, it worked like a champ EXCEPT for the rear glass on the hatch. The water droplets left from the car wash literally did not move an inch and virtually dried in place.

I've looked for some type of wind tunnel test videos on our car to no avail. But because of what I saw, and the fact that the rear wing is directly below and on top of the rear glass, I don't believe that the entire surface of the wing sees an appreciable amount of down force-generating air. I do think that the outside edge might... or maybe the outer half (if you drew a line across it in the center), but not all of it. I would guess the only way to really test this would be to tape multiple one inch long pieces of ribbon all over the rear wing and watch how they move while driving. This will also probably make the car look like a runaway gay pride float, so I probably won't be attempting it.

I could be wrong.