Hello,
My name is Natasha and I have a silver a4 (b6) 1.8T quattro.
I'm pretty new to the forums although I do have extensive knowledge on cars in general because of my house full of men and a genuine interest in German cars (Ich bin Deutsche). I'd really like to trade my exhaust system too!

http://www.goapr.com/products/apr_exhaust_8ea418t.html - "APR's B6 A4 Exhaust is a complete stainless steel, mandrel bent, cat-back exhaust. On an A4, the catalytic converter is bolted to the turbocharger and then the exhaust begins with the downpipe. Unlike most other aftermarket exhausts, the APR exhaust includes a 2.5" downpipe. APR has two different exhaust systems available for the B6 A4, the Stealth and the Sport. These systems are a complete package replacing all of the tubing from the OEM catalyst to the polished stainless tips that are acid etched with the APR logo."

I'm pretty sure mine is the SPORT model (w/o center muffler). This upgrade was a gift, but I'm a woman and it's a bit much for me.
I'm willing to trade for another exhaust system and I don't mind a little engine purr, but I don't like to disturb my neighbors with my current sporty exhaust.
I'd also consider swapping my sport model for the Stealth model.