Honestly, It is all trial and error, you may come up with something that has the worst sound imaginable, but then again, you may just "hit the nail on the head". I personally have always made 2 initial mods to my vehicles, and my Murano was no exception. I put Flowmasters on everything I drive, and to help the vehicle "breath" properly, I normally add a K&N, however in this case, I added a Fram Airhog because I found them for less than $10, check this out:
http://www.amazon.com/FRAM-PPA...r=1-2I stumbled across this a while ago, and I am surprised there are still some available!!
I like the sound of mine, I think it sounds like an FX 45, but "throatier" which was what I was looking for. The sound is a little louder in the passenger compartment as to be expected, but if it really bothers your ears, I am sure you can use some dymamat or something to help reduce the "cabin" noise.
Just for anyone searching:Flowmaster P/N 42583 is pretty much a direct fit, Single in Dual out 2.5" in/out, it is actually for the 82-02 Camaro and I believe Firebird/Trans Am(2003-2008 Murano) Fram P/N is PPA4309. K&N is 33-2031-2
for anyone wondering, this is not mine, but sounds very similar to this clip:
http://www.youtube.com/watch?v=FpyCjgnloQc
Anywho, enjoy!!Thanks"86"