Steve,
Just had exactly same problem only after finding the bolts in teh misc bag I found threads were poor in roll bar and had to be cleaned out with a tap to stop them siezing up - they are 3/8" UNF which is not a common thread these days!!
Did you get an instruction leaflet on fitting the petty bar (i.e. how is it mounted in the passenger footwell) and headrest restraints?
Steve