Accelerating between about 1500 rpms and 3k rpms, with the window down, I can hear what sounds like a high pitch whisle....it does NOT change in pitch, and it is not loud. It sounds a bit like on a car with old belts that slip...Except mine is brand new with 4k miles, and its quieter. I've heard one explanation that it was a rear main seal vacuum leak from someone else's diagnosis. Any other ideas on what it might be? Thanks.