just went to dealer today to check the noise after 5k rpm when you press clutch howl sound.
but what infiniti told me is that they cant fix it, they dont know what's wrong and they are not willing to take apart to fix it unless i pay them for it. the only way they will do/fix is that only if nissan/infiniti recall the car. but what they suggest me is i can write a letter to infiniti to complain about the noise and have them to come up with a solution.
so i think i'm going to write a letter to infiniti canada to see what to do

 

You may as well address the letter to Infiniti global. This symptom is standard in the 6MT. If you do a search, you'll find about 1, 000, 023 threads about it.

 

I'm usually shifting so fast at 5k rpm, that I don't hear anything.

 

I have an 05 6MT (1700 miles) and have the same howl. I agree it doesn't sound "normal" but would I say it is a sign of a "defect" or cause for concern? Only time will tell. I share your concern, however, have accepted the "howl" as a "feature of the car". Be comforted by the fact that it is not just you, but many others who are experiencing this. For now, I'll put my faith in the build quality of the car and, the warranty as a backup..

On a diff note, I have had the car back to the dealer for bad O2 sensors (apparently these things are more sensitive than females). Counting the original one, 2 have been replaced. Hopefully this 3rd one is the charmer.
Not to ramble on, but I also have "clutch chatter" when releasing in 1st and 2nd gear - my service advisor said it is normal and attributed it to the throwout bearing.

All in all, I love the car and have no regrets after 1700 miles..