Our 2003 V70 has a slight high pitched ringing sound coming, maybe, from the center of the dash console. It comes and goes and is hard to determine it's origin. It seems to be not affected by speed, wheel turning, braking or accelerating. Doesn't matter if the fan or AC is on or off. And it's been heard with the radio off. I've only heard it a few times and never heard anything like it before. It almost sounds like a soft electronic bing as you might hear when a door is ajar.

Any ideas?