Installed a new muffler....
Not the most exciting thread in the world, but it was pretty cool. I got a Racing Beat muffler from Gary at TDR, and it went on in about 30 minutes without even jacking the car up. I used PB Blaster on the bolts and WD40 on the rubber hanger things.... If anyone is considering doing this, it's freaking easy!
I got a pretty mellow sounding muffler, which is what I wanted, and really like the way it sounds.
I'm thinking suspension might be next, or possibly an intake improvement.. Or a header..