There has been some discussion of the rear facing seat so I thought I would
post some pictures of what it looks like in my 1987 westy.  It was a factory
or dealer installed option.
The seat flips up which gives more space when not in use.
Also, it removes very easily with just one spring loaded pin.  Not too heavy
either.
There is a shoulder seat belt as well.
I think the rear facing 5th seat (for westies) is better because it does not
take up as much space as the type that fits on tracks in the middle of the
floor.

I have never used this seat though, just two of us in the van.

See http://www.geocities.com/ftpspace1/seat.html

Gary
Calgary, Canada
1987 Syncro westy