the resonator is like a muffler. Under the car there is what is to appear to be a muffler toward the center on the car, that is the resonator. The back muffler is the muffler the center one is the resonator. give that a try if you are satisfied then try a muffler with the resonator back on. I say to put the resonator back on because you dont want it to scream. if you want the car to have a great rumble then go with borla, here is a link to get them on the cheap
http://stores.ebay.com/Wicked-Nickys-Exhaust_Borla-Mufflers_W0QQcolZ4QQdirZ1QQfsubZ17QQftidZ2QQtZkm