I was looking at something to enhance the already sporty appearance of the GTS back end and I had been looking at the Akrapovic rear diffuser. I wasn't sure if it would fit over the stock exhaust and I asked Akrapovic directly and they said it was made for theirs and wouldn't give me any dimensions to compare (I didn't know if the outer diameters or spacing would be a problem). I called Flat 6 Motorsports to ask them and they were nice enough to send me some photos of a tape measure with their exhaust and diffuser so I could get a warm and fuzzy feeling about dimensions before I ordered the part. My dealer installed the part for me while they were replacing the dash (leather was pulling up) . What a difference! It is just what the back end needed to look a little more aggressive.