Okay...I changed the picture above so you can see better now.
And if you can dream it...I've probably taken a picture of it...so here you go. Notice that he took the black all the way around the outside of the tip surrounds which is a little different. There are quite a few weird edges and lips on the rear spoiler and deciding exactly where to stop the black became a major decision. And apparently we all have different opinions because I've seen it done every possible way.
I had the square tips at one time....but they vibrated against the surrounds and made a terrible noise. After two failed attempts to make it stop...I downsized to the ones I have now.
And here's a nice comparison pic...my lowered LT with GM GFX (and Havoc rear spoiler) next to a stock LT.