Clunk noise comming from rear

[Spanky]

I have a 2000 Boxster with a strange clunk noise coming from the rear of the car.

It only makes this noise when I have stopped and am starting to move forward again.

If you made me guess, I would say it's an engine mount or drive shaft that was slightly loose thereby allowing slight movement of this item once I have stopped the car and then taking back off.

Does anyone have any suggestions on what to check? I have checked drive shafts, the front engine mount and miscellaneous bolts that are part of the suspension, but I have not found the culprit of the clunking noise. I have found some bolts that I tighten up a little, but none seem to make a huge difference in the noise.

If anyone has any clues I would love to hear them before my clunking noise becomes jackpot noise for the local dealer.

Thanks for the help!
Chris