**** man...i really hoped it would have been fixed for you!!
At least its been reduced a lil bit, how loud is it now? can you still hear it even if you have the aircon on/ or radio on??
From here i would get the general manager in your car to hear it and really if they can't fix it demand they replace the car, you didn't pay your hard earned money for a car that makes abnormal noises and ruins your driving experience.
I actually just test drove a black 370z auto 30 mins ago and this time made a point of listening out for this sound you guys are talkin about. Basically i drove the car as i normally would and could not hear any noise. Then i went through 1 by 1 turning things off to see when i could actually hear it.
Whilst driving - windows up
1. Had the radio on and aircon on - couldn't hear it
2. Turned the radio off, aircon on - still couldn't hear it
3. Turned the aircon off, basically everything off, windows up and i could hear a very faint sound, my girlfriend could hear it too
She said as soon as i turned the aircon back on, on the lowest setting, the sound vanished. I then turned the radio on too and of course she couldnt hear it at all. This car had 20kms on it and was brand new but it was a late 2009 model bordering on 2010, so i really wonder if the sound would get louder/worse or effect earlier models more??
I am going to test drive the car again next week but for a few days this time to see how it goes, i totally forgot to lift the hood and listen for it so i will do that too. Going to get my brothers and friends ( all around 20 years old ) to listen out for it, see on a scale of 1 - 10 what they would rate the sound at.
It's possible that all the cars have some very low sound that is not noticable but just over half of the cars are effected by this being louder than the rest being the ECU and or wiring (based on what people on this website and friends who own have told me)
The dealer i went to today was really the nicest car dealer i have ever met, he was above and beyond normal experience. I told him about this website and the only thing stopping me purchasing this car is the potential ECU sound issue. He guaranteed if it happened he would fix it no matter what it took, i'm sure he would even give me that in writing too, which i would need before i bought the car, i will let you know how i go.
Thanks for reading my long *** post! And i really hope you guys with the issue louder than normal, i really hope it gets resolved for you so you can enjoy the car
Peace
- Ty