The pedestal single seat assembly uses the same floor rails as does the
ubiquitous double seat; it simply bolts right in.   Since it swivels, it can
be used as front or rear facing (or sideways if you want to emulate the
front seating experience of many city busses, or NYC subways.)  The seatback
is shorter than the front buckets, and has no headrest.   It has the same
seat attachment tracks as do the front buckets, so it can be simply slid off
and exchanged with any other Vanagon bucket seat.

I obtained a brown one of these this fall and intend to switch the seat with
a spare blue front bucket, so that it will have matching fabric to the rest
of my seats.

BTW, the existence of a "spare" front bucket does not indicate that riding
shotgun in my van means sitting on an orange crate.  Rather, when the
opportunity arose, I upgraded from standard armrests to adjustable armrests,
by replacing my 1986 front seats with those from a 1987.  (Apparently 1987
was the first year of the adjustable armrest.)

I also have installed one rear facing, removeable jump seat behind the
driver's seat, but it gets rare use as few of my passengers enjoy riding
backwards.  The jump seat could actually be used in conjunction with the
pedestal seat if the pedestal seat were simply mounted behind the front
passenger seat, instead of in the middle position.  However, it is my
intention to typically use one or the other middle seats, not both
simultaneously.

Budd Premack
86 Syncro, 73 Super
Minneapolis, MN (Land of Frozen Waters)