timmus
A2OC Donor
Part 18A is the plastic hinge part of the false floor itself. You don't need to buy it as it comes as part of the floor.
33 is a captive nut and 26 is the bolt (Torx40, if I remember correctly). You'll find that your car already has the captive nuts fitted in most of the holes, though they may be hidden behind the bitumen sound-deadening stuff (that you'll need to completely remove). You'll need about 10 of the bolts (part 26), but none of part 33.
Cheers,
Tom
Just to correct myself, the bolts mentioned are Torx45, not Torx40.