unfortunately there really isn't much you can do to the piece that's on the ES/base models. There actually are two housings for lightbulbs (which does kinda prove that on the Stealth and 3000GT, that piece is very similar.. just the Stealth's is a little "thicker" from top to bottom).. if you don't mind hacking away at it, you might could try to install some lights back there.. the entire unit itself is held together with some sort of epoxy, and it very difficult to disassemble..
so really.. the only thing you could do, is to either add some lettering (like Deathsled), or you could paint it.. or, get some "Niteshades" and black it out, along with your taillights. unless you feel adventurous and try to put some lights back there.