Water in boot after rain - following garage tailgate repair

[Harry]

I suspect the rubber seal trim was put back wrong. So will remove, clean (and bodywork) and replace, with an added silicone bead around the underslde.

Has anyone come across this problem previously? I'm also looking at, and wondering about, the triangular rear side-windows, as a possible source.

I'd be grateful for any ideas ... and a Magic Wand!

H