Just want to add one thing to this thread on the memory foam mattress
toppers.  Mine is about 2" thick with the cover, direct from Costco.  I find
that I dont need to roll it up to get it out of the way when the rear seat
is up.  It folds over just once, no hassle, and fits perfect behind the rear
seat.  Takes some room but still plenty of room for other things.  I even
store my Lafuma folding chair between the folds.  When ready to make up the
bed the seat comes down and a simple pull on the topper flops it right into
place.
And as for comfort, I sleep better in the Starwagen than I do at home.