Update: I installed a third lap/waist belt in the '82 Westy.
Couldn't find any place to buy one locally in Edmonton, so I
"borrowed" the one from my '94 Eurovan Westy.

The seatbelt spacing is not even in my '82. The seat next to
the rear closet is very wide, while the one next to the sliding door
is narrower. The mountpoints in the middle are really close,
so the third seatbelt position is the narrowest, but works for
a small person.

When I have more time I'll look into the shoulder belt upgrade.
I didn't get an answer to my question if someone has installed
the front belts from a bay window westy ('72) in a Vanagon. Any hints?

A related topic, someone has a picture how the seatbelt is installed
for a rear facing jumpseat? Particularly how does one place the
roller/wind up mechanism on the pillar? (There already seems to be
two mounting holes for the upper D-ring that the belt slides though.

Thanks,
Martin