Anyone recognise this part?

[MysteryMan]

This might be a red herring, but, my wife noticed a small plastic "thing" underneath the back end of my Mk5 Golf GTI and I am not sure if it has come from the car or something else!

I am hoping that some of you experts can tell me if you recognise it as something that might have fallen off.

I have put a link to some photos here.....
http://s670.photobucket.com/user/MysteryMan2/library/VW%20Part
.....and you will see from the 5th one that part of it unscrews. To me it looks like some sort of connector for a pipe, but, could quite easily be wrong.

The only marking I can see are a couple of "+" signs. Certainly, there is no obvious part number.

Any thoughts? 

[Teutonic_Tamer]

I have put a link to some photos here.....
http://s670.photobucket.com/user/MysteryMan2/library/VW%20Part

"Problem loading page" - double-check the url please.

[Rhyso]

I have put a link to some photos here.....
http://s670.photobucket.com/user/MysteryMan2/library/VW%20Part

"Problem loading page" - double-check the url please.

Loads ok for me? 

[Teutonic_Tamer]

The 'bucket must have had some down-time.  Now working fine for me! 

That is the tailgate stop buffer.  They will drop out if some cack-handed amateur has fiddled with them!