wings belong on planes...not on cars...
thats my opinion.
Ok look, those wings are very functional on cars that actually need them (tourismo). But you'll never really be going that fast for long (Highway certainly doesnt count because its a straigh line). You just dont NEED one...and theyre so fricken tacky.
I saw a corvette w/ one yesterday and it looked decent...probably becuase it was so low key, maybe not even 6" high...but youre probably planning on a 9"-er right? .....
edit**ok I just thought of this...how about a Mugen (even mugen style) wing...it looks good on the 4drs. Check into those, Im sure you'll like it

(There is a really badass one @
www.jdmfan.com, you have to become a member to see the pics...but its worth it..."See the light")