Im running a striaght through exhaust on my 12a turbo, buddy it's loud. So, I started looking at alternative ways to quiet it down. The in the muffler insert worked kinda, but its ugly as all sin. I found these while looking though a summit catalog and thought it would be worth a try.
http://www.carchemistry.com/ccinserts.html

Mine arrived in the mail today. I figure just stick it in the pipe. I'm going to get a little video of the car tomorrow to record a before and after sound see if it really works.

Here are some pics