Hi Ballie, thank you for the info, I hadn't realised the holes were threaded might try and find some domed headed alan key bolts to fit so I'm not just sticking the covers back on, if I can work out what size they are.Just the sealent round the boot hinge in that opening as i know thats a week spot on the mk7 Golfs as it flexes and then cracks if wind catches the hatch and makes it flex.
I have removed both the two black panels today and broke one of the plastic clip inserts like you did. Ive taped mine up with duct tape to test as you did. Its supposed to rain heavy in the morning so i will see if it helps mine. What got me was the black panel was loose on my passenger side but the area were yours is getting water is bone dry on mine. Mines the other side.
Just some info about these black panels from your photo discriptions. Mine have the same sealer as yours and my car was my late fathers from new before i got it over 8 yrs ago so i know whats been done too mine over time. So this is the factory finish. Why these plastic clips go into a threaded nut inserts is anyones guess.
Guess we will keep looking. Makes you feel like were missing something obvious though.