Roof-rack Gutter Strip trim thing (fitment)

[Mr_Orange]

Got a 3dr mk4.  Had to replace the black gutter strip on roof, across top of rear window after it "disappeared".
Not sure how to get new one in now?  I've given it a good shove down, but it looks half-in still?  Can't get it to sit right down in the slot (with top edge level / flush).
Any hints on fitment?  Should it be taken apart and the rubber bit fitted first, then top trim popped into that?
Ta 

[Steve_PD]

Should just pop in place, I haven't got any on mine as they also disappeared 

[K666PDP]

shood fit in nice and tight, open tailgate and pull up rubber above door and locate in little notch in rubber above door and make sure its flush fitting against bodywork  there should be no gap between the trim and the rubber and make sure its nice and snug fitting.....if its not then ull lose it again as the wind drag will 'rip' it off!!!