i have the same clunking in the rear only over like speed bumps and stuff almost sounds like the rear dampers are loose or something.

Yeah thats the problem I found...I couldnt find anything loose in the backI have the same issues, I found that my front sway bar links have some play in them and I plan on replacing them to fix the problem
try gutting your liftgate.... a slight "clunking" would be the least of your noises!yeah I have the slight "clunking" also...i found that the trunk lid does have a lot of play in it with the rear hatch closed (I have an '03 SVTF 5-door). I bought some rubber feet from radio shack, positioned them so the rubber stops on the trunklid hit them and when closed, the lid is secured. I pass off any other bumpy noise as the taught SVT suspension. It should be noted that after i replaced my Conti Sport Contacts with a set of Cooper SLE Sports, road noise was drastically less.