I bought a pre-owned G35 and it looks completely stock besides the rear and back window is tinted.

I popped the hood today and noticed the intake tube is black and straight and there is a "Z" marked on it... I was curious to know if this is the Z tube you all must be talking about, Sorry no pics but I can get some up if you guys want.

 

This is Z-tube

 

No you don't have the z-tube, I went through the same thing. The tube u see has these extra compartments stickin out which actually baffles the sound. Replace it with the z tube, a straight tube and best for your buck mod wise, to pretty much get a better sound out of your engine over 3500 rpms. No real hp gains, maybe 1 or 2 hp.

 

^^^lol went through the same deal when i got my used G....i had the same Z marked on it also. sorry but its not it.
but you should def get it

 

haha.. ok.. I just wasn't sure since this was not brand new and the previous owner could've done the Z tube... I may decide to get this mod... I love the sound of the stock exhaust and would only try to enhance that sound not change it.

 

The name 'Z-Tube' simply refers to the fact that the intake tube is original equipment on 350Z Z-car's VQ engine.