general problems of the 2012 Mini Cooper

Driving 45 mph on busy city four-lane road, I braked gradually in approach to red light, which is my normal braking style. Car did not come to a complete stop--brakes only worked to a point but did not completely stop car; simultaneously engine revved to very high rpm. I threw transmission into park and turned off ignition lest my car ram car ahead of me. Very frightening. At previous two lights I had noticed that brakes were acting funny, not bringing car to a complete stop but I had left plenty of braking distance and was able to let car roll to a stop, in spite of brakes not effecting a complete stop . At those two lights the runaway engine (high rpm) did not occur or I would have pulled over right then. However, engine revving to high rpm has also occurred occasionally when pulling into garage but I had not given this a lot of thought because I have quickly turned off ignition. Now I know it's very dangerous situation. Of course I am not driving it but am having it towed to dealer for repair. The car has been serviced regularly at dealer and has 24,239 miles on it. There has never been a necessity for repairs on this Mini Cooper clubman.