Does anyone have this problem with their Buick Rainier? Whether I am going slow or fast, every time I drive over a bump in the road my Buick is squirrely and it feels like it is fish-tailing. I have almost gone off the road a couple of times. I thought it was my air bag, which had a leak, but I got it fixed and my Buick is still extremely squirrely. When I drive it sounds like something is loose in the back of the vehicle. I am not sure what the problem is. I appreciate any help or suggestions!