ever since ive had the V, its had great brakes compaired to my n/a. altho i keep noticing something, and im not sure if its supposed to do it or not? if im braking hard the brake pedal is firm, and doing exactly what it should be doing, it moves down about 1 inch. but, if i go over a bump while braking hard, the brake pedal jumps down about a further 1-2 inches... the car is still braking as hard, but its just worring when your tying to stop in a hurry and the brake pedal is moving around!! any ideas what it could be? is this a common problem? or is it just mine? it had new front discs, and all new pads when i bought it, and the brake fluid level is perfect.