ive seen a bunch of vanagons that have the lower edges of the rear hatch
rusting out from behind, and bubbling up the paint, rotting right thru the metal.
didnt think much of it till the other day after a torrential downpour the day
before, i raised the hatch on my vanagon and a little bit of water dripped
out from around the bottom of the hatch.  upon closer inspection i noticed a
bunch of water was in the bottom lip inside the hatch.   standing water creates
rust.. so i  was thinking of a way to let the water drain out of there, and to
never build up in there again..  then i noticed the 2 black plastic round
plugs in each bottom corner of the hatch..  i carefully pried these out with a
small flathead as to not scratch the paint..  upon which i was immediately doused
with water.  i removed these 2 plugs and will not ever put them back in, as
they hold water inside the hatch, wich leads to rust..

just a helpful tip..
chris