Ok, this one has me stumped. MY 98 D1 starts to make a hight pitch squeal after about 20 min of driving. It sort of sounds like a brake pad rubbing, a high pitched loud squeal. but upon inspection, nothing is out of the ordinary. When it is making the noice if you hit a bump, or turn the steering wheel or touch the brakes it goes away for a few minutes and then comes back. I also had it in to my local shop and they didn't see any thing dragging or rubbing as far as the brakes were concerned. Any idea what I should check now?