Recently purchased 93 SSE, 114,000mi. Needed struts badly. Replaced (4) struts and mounts. All rear suspension professionally checked and is tight. I have also greased everything thing that will take it. Have an annoying intermitent popping noise from rear/underneath when getting in/out, taking off from stop, hard braking and on rough roads. Pop is metalic and can sometimes be felt in the rear floorboard. Sounds like it comes from both sides but predominately passengers rear. Pop is more frequent with passenger in front or rear. If using a floor jack I can recreate the noise if I place the jack in the middle of the "frame" that runs between the strut towers and lift slightly. Can't find anything loose or that looks like it has had movement except the heat shield that attaches at the rear floorboard. Not the same noise, but I did drill and replace the loose rivets. I scare people in the other lane when I take off and it is bugging me to death. Any ideas would be appreciated.