Magnaflow catback, if you want a nice deep subtle sound, this is what you want. $700 shipped (Paypal welcome, but add 3%), Just like the link below, but with out the X pipe. This is catback only.

http://www.pfyc.com/pc/VT5026/VTEXH/...aust+-+C5.html
I took this picture today, to atest of the cleanliness of these.