The clip indeed secures the connectors to the body - you see the slit in the first picture? that is where the clip slides into... that slit is on the right hinge housing of the rear hatch - the left hosing does not have such a slot for a clip.

i have put the spoiler back together and clip is back there now , so i can't take another picture, unless i pull it apart again...

this is not an imperative to have this part number - it is just in my quest to use the factory connectors for my retrofits, I was looking for a 2-pin OUTSIDE connector with both mating parts and this one was perfect to have... usually you can find just one half of the set - the mating half is integral part of a module, and in this case there was a complete set...