I recently had my original muffler replaced under warranty because it broke cleanly in half on the thinner neck pipe, but anyways my new muffler has a serious vibration issue at 30-58 mph, also when I accelerate quickly, it drowns out the engine noise, I've narrowed it down to the heat shield, it moves and vibrates and I can't get it to stop, I've tried stuffing some foil between the plate and muffler to put pressure on it, it worked! for about ten minutes until it vibrated out, please someone tell me that they're having this issue and possibly a fix because it's driving me insane!