Weichers rear upper strut brace fitting in polo 6n2 gti

Can anyone give any advice or point me in the direction of any fitting instructions? It seems to be drilled through the bodywork i.e. it doesn't go over the strut tops, and a nut and bolt fixing. Would something like rubber washers be used to prevent water getting in through holes/fixings?

 

Have googled but so far nothing.

 

I would paint a thick seam sealer on the bolts where you can see them under the rear arches.

 

Ok. I will have a quick search online for some.