Now you mention it, like gsd2000 says I don't think I have them either. I just have the useless space saver (which don't fit) a crap jack and a can of tyre weld. I will have a look in the manual tomorrow and give you a shout if you don't have one.
I looked at that spreading the weight bit, but no way do they fit anything under the car? so odd what they are for, seems like no one else has them so far
Its a usefull boot in our cars, the jacks a joke, the yellow thing to remove the nut caps is utterly useless, the spare I wouldnt dare drive on it especially on the back, not much of anything really!!