[s-cars] Avant rear hatch water leakage question

[Dave Forgie]

I was looking at a 1997 A6 Avant today (Plan B as to how to have an
S-car avant if transport Canada kills the 15yr exemption rule).  The
sales guy on the lot open the hatch for me and as he did so, all sort of
water ran out out of the hatch as it was raised.  When he opened up the
rear third seat so I could see the spare (small donut), there was water
in spare wheel well. 

Admittedly, this is Vancouver and we just got hammered with rain
yesterday (4 inches or so) BUT, to me, there shouldn't be any water
leakage at any time.

What could it be? What are the usual suspsects?  Window to hatch seal?
Hatch to body seal?  

TIA

Dave F.