Thanks to all who have replied. I am not so much looking for the sound to be a lot louder. I want to couple a new cat back exhaust with a cold air intake to increase the horsepower just a bit. I want the car to look stock/ I am not looking to modify the engine in any way - I'm still under warranty. For Johns350, where did you purchase your NISMO cat back and how much did you pay?

 

I got mine at Texas Nissan of Grapevine - if I remember right, it was @$1100 installed. When you purchase (and get it installed) at the dealer, it comes w/3yr-36k warr too.

I haven't done anything on the intake side yet - other than a K&N drop-in filter. One day I'll get around to doing the intake spacer - probably more beneficial than cold-air intake on my '06.

Thanks