I get this whine too. Mine is an 03 with only 11k miles. I noticed it first when i raced my friends z in my gsr. His whined and almost sounded as if a turbo was spooling up. Now that i have my z, mine does it too. I think it is something that most of our cars do but some peopel dont notice it because it only is audible at certain rpm and when the accelerator is pushed a certain amount. I personally like the sound, makes my car sound FI. lol. I just put a pop charger on, and it makes it even more pronounced. Also u can get it to "chirp", just do a little quick whistle/whine by tapping the gas. I dont think anything is wrong, though im not sure why the car does it. And to me, before and after the popcharger, it sounded like it was coming right from where the air filter is. Just my thoughts, if u cant get it to go away, just learn to love it. And if u want ur car to sound like a race car for 120 bucks go grab a pop charger. Best $120 I ever spent.