I installed a pair of Rob's cat delete ss downpipes (without cutouts) on my SSB SRT6 roadster and I like the improved sound and slightly improved performance. Not cheap and a difficult install if you have to crawl around under the car up on jack stands (I don't have a hoist but am now considering one). If I do get a hoist I will probably do the cat delete downpipes for the black SRT6 roadster too as I like them that much.