My thoughts are along the same theme except I didn't like the "Round hole in the Rectangle box" look"................SOOOOooooooooooooooo......... .
I cleaned the INSIDE and outside real good and then painted the inside area with Hi-Temp Black so from a distance the exhaust is TWO RECTANGLES!
Also, the soot that builds up inside can be cleaned or left alone, I only worry about the shiney outside and the lip now. :wink: