When i put my car into reverse, the car 'reved up' and began moving forward. with all of my might, i pushed down on the brakes. the car was still moving forward, so i then put the car into 'park'. at that point, it made a hideous grinding noise, so i immediately turned the car off. about 30 seconds later, i started the car and it sounded fine. i then drove the car home, (about 5 miles), without incident.