Noise coming from the back

It's been nerving me for a year now, every time I hit a bumb there is a noise comming from the back, like something was loose. it doesn't come from the inside, and it's not the tail gate.
What could it be?? :unsicher:

Well... There's actually not too many things to be taken into consideration. Maybe the mounting of the exhaust? Is it certain it is not coming from the inside?

I dont think it's the exhaust, cause it makes the noise also with the original exhaust. I would say the noise is comming from the right, back corner.
I still need to see if it's not comming from the inside of the tail gate's plastic panel. I have taken every other panel away form the back but I found nothing suspect.
I have already changed the rubber bumpers for the tail gate.

I was also by the local ACL (adac) and they checked it out and said to me that the sway bar's fixation is loosing oil

Well, that's odd. I've been harrassed by the tools and the styrofoam they've put around the spare-wheel well. But that indubitably comes from the inside.

How exactly does that noise sound? I reckon it's some kind of tictacking? Or maybe a rather squeaky noise? Have you had a look under the car at the suspension?

The sound is the same like when you hit slowly a wooden table with a spoon
and this 2-3 times always when you hit a bumb on a normal street.
Yeah the mecanicians took a look under and found nothing.
I've been under also and everything seemd to be tight.
All my tools and spare wheel are tight too.

Thanks.

I'm quite sure it's the rubber dampers of the trunk lid. Look if they are cracked,, if they are, it is certainly them.

I've changed the rubber dampers to new ones, last summer.
Thanks