I heard about the functional wing on the evo, and it got me to wondering, and looking at mine and wondering if it's functional. Can anyone answer my question?

nope, unless you drive 100+ daily, it'll be a tad bit functional.

but most will say no.

If you can push down on your spoiler and it flexes easily it's not functional. The Prelude wing is not functional.

Yes, to a very conservative degree. It does not provide downforce by itself. More like it alleviates lift. The air traveling over the top of the car would have a tendency to follow the lines of the body all the way down and off the trunk without the wing there. That air following the body down creates a low pressure area(lift) With the wing there the air will tend to come off the back window and go straight over the wing. That limits the low pressure areas on the back of the car. No downforce produced just lift eliminated. Think of a stock ITR wing it works the same way only it causes the air to come off the hatch a little earlier. Then there is the Mugen ITR wing. It catches the air coming off the top of the roof so the hatch is almost ignored entirely. Hope that helped.