I have an 84' Westy and I installed the tracks for a 2 person bench seat from a passenger van.  When I need to carry five or more people I slide the seat into the tracks and I remove it when not needed.  During camping, I'll pull the seat out, rotate it 180 degrees and put it back in so that it faces backwards.  With this arrangement my two pre-teens sleep up top, my toddler sleeps on the bench and my wife and I sleep on the lower bed. 

FWIW, I did install a third set of safety belts in the back in case I need the extra capacity carrying youngsters around.  I know there is not a substitute for safety, but when I was kid, I played in the back of a VW bus, or on the floor, or just about anywhere while we were going down the road.  You just didn't worry about seat belts when you were in a van traveling.  Now, you take your kids and harness them into a contraption so that they cannot move and expect them to sit still without crying for an 8 hour trip. 

Just a side note on safety.  During trips after I had my driver's license, my Dad would make me switch to the driver's seat while we were going down the road, because he didn't want to stop.  How's that for safe driving?  If you had to use the bathroom, you either had to use a coffee can or a port a potty.  The only thing you ever stopped for during trips was gas and that was it... 

David Wilhite 

84' Westy