Like everyone else, I say go with the Rear Fog lamp, it looks great.
I installed it on my 40th, and added this intelligent flasher to it.
Intelligent Brake Light Flasher - $29.95 Comagination VisiStop
It looks like an F1. A cop pulled up next to me once, rolled down his window and asked where I got it, he really liked it.
If your stuck on going with the stock black cover, PM me, I have one in the closet somewhere.