I've got one too, but mine only appears when mobile.  It is unfortunately, very consistent.

  It started a while ago as a faint "squeak, squeak" when rolling, but has now developed into a "SQUEAL, SQUEAL SQUEAL" that turns heads.  I originally suspected a warped disk/rubbing caliper; alas no.  It seems to be coming from the rear passenger side and it is only present when the engine is delivering power.

  It doesn't matter how much power, the squeal is the same, it only changes in repetition rate as the speed goes up.  It disappears instantly when coasting or when the clutch goes in.

  The weather has been too cold and... O.K., I admit it, I'm too chicken to crawl underneath lest I find something horrible.  I suspect CV joints or a rear wheel bearing, but I'm worried it might be the gearbox or final drive.

  Any suggestions?

  Niall