I drive and quite honestly ADORE a Crystal White 03' Sport Design GS300 (my 3rd actually-hence the screen name) that has a very subtle trunk wing that looks like what you are after. It looks simliar to this at the l-tuned site... http://www.l-tunedparts.com/product/?id=935 You might want to search around. I would think you could get it for less somewhere. It adds just the right amount of "flair" without standing out too much.
I'll have pics of the wing and of my baby girl in whole up next week once the BBS come to town :) :D ...I scored a staggered set with 18x9 rears and 18x8 fronts...THANKS SANTA. I just learned a new twisty way to work and apparently you got my wish list....God Bless good wives...Happy Holidays to all....~cjw
