So I got a nice used Borla (muffler only) from someone who had it on an "07", for $50.
This morning I had it installed with a fabricated "Y" post resonator, $150. sounds pretty good, a lot deeper and I can really feel it when going through the gears. Not so much of a power difference, but I can feel a difference with shifts, they seem more responsive (5AT). Think it would make any more of a difference with an after market resonator? I already did a K&N/Z-Tube.

 

MPG before muffler ~18.8, reset, just checked today and I'm at 20.2 and I have been rallying quite a bit since the install. Best mod for my my money so far. Coupled with the intake my butt dyno says 20 HP LOL.
Seriously, I lost that signature G sound, but the Borla is deep and it is really a night and day difference from a performance perspective. No it aint no turbo, but what a difference.
Will an aftermarket resonator (or none) make it too loud? Pretty quite after the swap....

 

"Too loud" is a personal preference my friend... If your going for more power breather mods are your best bet. Also these will affect the sound of your vehicle.