Every know and again im getting a high pitched what i can only discribe as a droaning noise. It isnt there ALL the time, i can drive for miles and miles before it does it then it suddenly stops randomly. Sounds like its coming from the rear wheel if i hear the noise then turn slightly left or right the noise dissapears?!?! if i brake very gently the noise dissapears? noise is only there when driving in a straight line... any ideas? could it be bearings? only i thought bearings get louder when you turn left or right??