I recently went through and replaced a lot of the bushings in the front of the car. Ever since then, I get a small "clunk" when I go over bumps. It only happens when I'm driving on a really bumpy road or hit a pothole or something like that. If I'm on a relatively smooth highway, I hear nothing. It almost sounds like its at the upper shock mounts but they're tight. I've also been under the car and double checked and re-tightened everything but found nothing obvious or unusual. Does anybody have any suggestions?