The whine has been supposedly determined to be coming from the ECM which is mounted behind the glove box. Someone here had it replaced and it went away so maybe that's it, maybe not. I'll wait for more than one person for 100% confirmation. I can only barely hear it in mine sometimes if the radio is off and the windows are up and I'm just sitting still at an idle. As for the harshness above 6.5k, remember even the car you were driving only had 150 miles on it. I noticed on my Z that it wasn't until at least 400 miles that it actually felt like it wanted to rev up more and more. In fact it was quite a dog until at least 300 miles. I'm only at 600 now and been getting on it a little more and can feel and hear a huge difference. I've read that these motors don't really perform until a few thousand miles. But even broken in the motor doesn't exactly make everyone happy with its sound in the higher RPM's, but to each their own. You either love this beast for what it is, a raw sports car, or pick something else. Enjoy!
