I just brought an Invidia exhaust for my 2008 G35 sedan 2nd generation. The exhaust is 2nd hand. When I first open the boxes I see that the welding of the exhaust and the quality look great and I was really excited to do the installation.

Disappointment comes after I do the installation as dispite the widen piping of the cat back exhaust, the car actually sound like stock and extermly quiet without any exhaust note. My old set up with OEM y-pipe and midpipe with custom Maganaflow muffler sounds much much much louder than the Invidia Q300.

On the up side, I do feel some power gains, the car do accelerate smoother throughout the revs, however, if anyone of you are wishing to get a louder exhaust, the Invidia cat back exhaust is not for you, and this exhaust must pair with test pipes or High flow cats to actually make any sound out of it. If anyone of you are look for a pair of CBE with minimal gain of noise and power gain, this will be the exhaust for you.

Something's amiss. I've had the exhaust for a few years now and although it's mellowed out, it's certainly louder than stock. I also have dyno gains to show for it.

Did you get the entire CBE?

I think I did...haha...I hope I did!
its from the catalysit convertor to the muffler

Yup, it's definitely one of the quietest cat backs out there. My friend has it on his car. My old Stillen catback-only setup was louder than his current Invidia Q300 + GTM RTPs combo.
As far as noise, Stillen, ARK and GReddy have the best and loudest exhaust notes IMO.