I currently have the stage 3 with dynomax resonator and plan on changing the rear mufflers but dont know which will fit on there. And is there any way to remove 3rd cat?

 

Magnaflow 11365 rear muffs FTW!!!

 

Get an XLR8 V2 J-pipe, removed 3rd cat, adds noticeable power and some additional sound (though less than I expected). You can also get a test pipe to replace the 3rd cat for $50-70 or so but don't expect much in volume or power, the 3rd cat is pretty decent for an OEM in terms of flow and based on the size, minimal sound suppression.

 

Just found this,

 

jesus..whos car is that......looks familiar ^^