Can anyone tell me a typical mileage that the brake pads need to be changed for a 2001 GT? i have almost 50,000 miles. I looked at the pads and they look okay to me. Also I am noticing that when I drive around I hear a faintly quiet but HIGH pitched whistling sound when the car is rolling. The sound comes and goes, but I can easily hear it driving around at 30mph with the windows down. Then I slow down and it goes away. I don't think it would be a wheel bearing. Any advice is appreciated.