from about a week ago, my car has been making this tapping noise from the rear whenever i go over a bump or any irregularities on the road. at first i thought it was my itr sway bar that i had recently put in. (with a bsq mounting kit) i checked the installation again and everything seems to be in order. then i thought maybe it was the interior trim in the trunk. i took the plastic trim out and the noise was still there. now i'm guessing it might be the exhaust system - my teg is a 97 and the muffler section looks pretty rusty on the outside. the knocking sound is gone when i rev the car when it's parked. only when the car is moving and the road is rough. anyone with this experience? what could it be? help!