When you are first leaving Porsche Southpoint with your new car, maintenance isn't something you're likely thinking about. The fact of the matter is that you are going to need to make sure your car is being serviced from time to time in order to keep it running on the road as long as you want.
If, after driving it for a while, you start to hear a kind of whistling rattling noise when you are coming to a stop, it probably means that you need to get your car into the shop for some brake service.
There are other symptoms that your brakes are going. If you are finding that you need more room in Durham to come to a stop, then your brakes are also failing. You should really make sure that you are getting your brakes looked at every 12,000 miles in order to have peace of mind that everything is ok.