There's a metal plate through which the door lock/ latch is attached
to the lift gate, also the two license plate lights are attached to
it.  This bare metal, not visible from normal standing position, was
apparently never painted and of course it heavily rusted.  (Part of
the reason for the stickiness of the rear locking mechanismWas this a
defect in my car, or is that the way the car was designed?  And do
they still do that?