I began to notice a squealing noise related to vehicle speed (not engine speed) a few weeks ago and I thought I fixed it by spraying some brake silencer on the front rotors (it seems to be coming from the front) but now it's back and worse than ever.

The noise is regardless of gear (when I put it in neutral while the car is rolling it has no effect) but the interesting thing is that it almost completely goes away when I accelerate. As soon as I let off the gas it appears, and as soon as I press the gas pedal even a little, it's gone.

Also, I'm ruling out the brakes because braking has absolutely no effect on the noise, but sometimes when I turn the wheels slightly, this does affect the sound. Sometimes it almost goes away and sometimes it seems to make it worse.

I had a mechanic ride around with me today and he suspected some loose piece of plastic stuck somewhere (seems like a strange diagnosis), so I checked everything out and I can't seem to find anything like that.

I plan to bring it to a shop tomorrow or Saturday, but first I'd like to know what I should be letting them do.

Can anyone think of something that could make a squealing noise (almost like a loose belt or bad bearings) that is independent of engine speed or transmission gear, that goes away under acceleration? It's getting louder and I'm afraid something is going to give.

Any help at all, even a wild shot in the dark, would be greatly appreciated.

Thanks,
Ric