I have the 2004 G35 with 80k miles, it's manual transmission, there is some noise like" thudding" from the front suspicion at any speed, so i had done my wheel balance and also did a tire rotation to see if the noise can go aways or not, I even bought one pair new tires from walmart and install in the front , but it seems all doesn't work, the noise is still there, any idea folks? compression rod? thx

 

I had that thud on my 105K mile coupe, ended up being a blown front shock. It started thudding before it "felt" out (handling etc) so if your bushings check out, that may be another area to explore.

 

I am assuming that if you replaced the tires that it may be speed related so you might want to check your front hub bearings for excessive noise