i dont see them being super useful. I think most people get them to say i gotz the jdm hotness and add some contour to their car. An advertiser (i think it was the nismoshop) has them on special for $125 shipped.
edit: it wasnt the nismoshop that had them on sale but Nismoparts. For the hatchback tho.
http://zilvia.net/f/advertiser-speci...-specials.html