Mac boom tubes. Basically a resonator so it doesn't sound like straight pipe ass and has a very aggressive tone. I don't think you can go much louder with stock cats and mids.
I have Magnaflow "Bullet" Race mufflers welded into the midpipe, SLP loudmouths at the back. The bullets are about 4" in Diameter, look the part number up.
This Combo sounds perfect in my taste.
Refined through the whole rpm band, decent while cruising and monstrous when I`m flooring it.
I have the Borla ATAKs. They are pretty vicious. Misfit_5.0 sent me a video/sound clip of his, and I was sold. They are amazing. If he's still on here, hit him up. They are F'n LOUD. I have an '06, they are LOUD. Good luck with your choice!