When I pull up to a stop light in my 530i it is difficult for me to make a smooth stop. I can approach the light with smoothness. I can slow the car from one speed to another without problem. It's those last few feet that I just can't get a grip on. The brakes make a little low tone vibrating noise and then grab the end too much so the occupants in the car are jerked alittle. It's annoying. Can anybody here tell me what his is?