i noticed today that in cold about 45 degrees or lower weather when i back out of my driveway and the car has been sitting awhile i hear a squeak from the right rear it seems rythmic with the wheel rolling but cannot tell all that well and braking stops it. no noise when i then go forward on the road. and no noise when backing out of parking spots when the car has been driven within 7 or so hours. and no other noises (except the ones that have always been there i dont worry about) that concern me. it seems like a wheel bearing going bad to me but it being so intermittent i cant really diagnose it well. anyone have any thoughts? go ahead and and do the rear bearings? or any other ideas?