The polymer section of the Pontiac strut mount holds a suspension component securely for many years until it begins to wear out. When it is beginning to wear out it will be most notable when your wheels encounter an obstacle on the road and the suspension system has to make an adjustment to smooth the ride once again. The Pontiac strut mount can be found in the center of the wheel's fender well. The top of the strut will be protruding from the fender well with the strut mount and its polymer components holding it in place. As time progresses and your Pontiac ages, so do the polymer components. The strut mount begin to crack and split as it hold the strut in place over time. Also common is the hole through it that makes the firm attachment to the strut begins to enlarge. This makes it possible for the upper portion of the strut to move which negatively affects the handling of your Pontiac. A driver might even hear a banging noise from either the front or rear end when the vehicle crosses over a hole and the road. This is the strut moving in its upper mount. An inspection of the strut mount is best done when the vehicle is lifted off the ground so the tension on it will be relieved. If there is any movement in the strut sideways when it is grasped then the strut mount is worn and replacement should be considered. If replacement is not done, the movement of the strut when the Pontiac is moving down the road will do nothing but increase. This will increase the vibration the passengers and the components on your vehicle will feel every time the vehicle is operated.