Originally Posted by 2bits

Holy crap. I was talking to my dealer about this EXACT same problem yesterday. Two different mechanics rode with me in my car, and neither of them could hear it. They didn't dispute the noise (they admitted that their hearing could just be poor at that freq), but neither did they have an answer.

I left saying I'd investigate on the message boards today, but that I'd be in touch.

It sounds like a whine typical of a bad voltage regulator or ground, but unlike that it doesn't change frequency with the engine RPM. It disappears when the car is stopped and idling. If you rev the motor (while stopped), the sound returns. But if you let off on the gas during this rev the sound will stop temporarily. The noise is independent of the radio (on/off), and seems to come from the passenger side, I presume the passenger speaker. It's a single frequency, probably 5k-10k Hz, not too loud. Can be very irritating in stop and go traffic! I don't remember when I first noticed the noise, but I want to say a couple weeks ago. I've had my car for 4 months, and it has 1000 miles.

The next step will be to disconnect that speaker and verify the source. Might also be good to find someone at the dealer who can hear that damn freq.

Did you have any problems finding someone at the dealer to verify the noise?

I was going to throw in an aftermarket DD Nav and speakers, and this might be a good excuse. I highly suspect it's just the stereo since it's only the passenger speaker. I'd think that if it was a general electrical problem, it wouldn't localize to one of the front speakers. You would hear the wine in both.