I had a cat back custom exhaust done on my t5r about a month or two ago. They used a high flow cat that they recommended to me, I forget the name of the company, and a flowmaster 40 series muffler. I wanted 3" all the way, but they said there wasn't enough room for 3" all the way, so it was 3" from the cat to the muffler where it was 2 1/2" to the custom dual outlets out the rear. They said the job would cost $420, but it took them longer then they expected because of the o2 senser that needed to go back in. So I gave them $450 for keeping their shop open an extra hour. Sound wise the car was pretty much silent except when under hard acceleration, even then it got loud(for a volvo). Now it rumbles like a 5.0 when at a standstill and sounds like a european sports car under acceleration, not ricey, but nice like an m3 or something.