1987 300TD Hatch and water ingress

[zu!]

So its been raining like the end of days here...and more to come. I lifted up the hatch the other day to load something can got the shock of my life...the little recess in the centre where the lock pulls the hatch in, was filled to the brim with water. How the heck is water getting into there?

Looked up, and see a small trickle of water seeping out from between the hatch seal and literally trickling over the plastic panel piece. The carpets are dry, even the rear hatch carpet is dry.

Has anyone had this happen to them before? What can I do? I hate the thought of water coming into the car and slowly eating it from inside out.

Also the passenger rear door window always seems to fog up. Signs of water ingress? Carpets are dry...