Greetings. Ill get straight to it, sometimes when I'm driving, and really,this only happens sometimes, whenever the MINI feels like it :( . Sometimes when I'm driving,and in traffic for example, my brake pad vibrates and the car makes a sort of whining noise ,even if I leave the brake pad,the whining noise is still there,just louder when I press the pedal in. Its only my brake pad that vibrates and the other pedals are perfect. And the next day I could drive and it would be normal again Not sure what this is, help? Thanks