Here are some pictures for a rear valance/center exhaust modification concepts.  Since Lotus went to the center exhaust in 2002 I wanted to see what it would look like on my car but I didn't like the aluminum panel that Lotus designed for the task of covering up that area.

Here's an original rear view with the exhaust tips enhanced.






......and my two favorites.

......and after much deliberation and a redesign I chose something completely different.  Of these two I think I am going to go with the one with the exhaust tips all the way out to the sides as it makes the car look much wider and the tips will fit nicely into the curves at the ends.