I wanted to relate my history with this problem  for my own education
(suggestions)
and hopefully to be helpful to others (my efforts to date).

About a year ago water started coming into the cabin during any significant
rain just in front of the gas cap door lock (next to the threshold). I
removed the inner lining (panel) and did the hose test. The water was coming
in
from both the speaker hole and from a small 1.5" hole above that. Drainage
holes in the bottom of the door were wide open.

I replaced the rubber window trim on the outside of the door to do a better
job of sealing the rain out as the old was a little stiff. This helped but
did not eliminate the leakage by itself.

So, I got some plastic and silicone rubber and sealed the small hole
outright. To solve the speaker
hole problem, I glued small sections of plastic (like from a plastic bag) in
an overlapping fashion above the speaker hole so that the sections would lay
over
the back of the speaker and shed the water past it and into the bottom of
the door.

Seems OK now.

My remaining question is "why did it start leaking at all?".  What changed
inside the door that sent the water up against the "inside side" of the
door... or is there an internal membrane in the door that has failed?

Thanks, Lar