there not the same and require a shit load of work to fit.
i know ive personally fitted one to my old car the sax06 from 106owners, that shitty primer white thing with chalk board bonnet.
allow a weekend should you choose to do it.
you have 2 options
1 as said you need rear lights which have to have 2 holes drilled in each side due to them being completly different to the saxo
then you can either resculpt bits where it dont shut with a hammer altering the line around the lights and and same on the tailgate
you also need different tailgate gas struts i used 205 versions as saxo ones dont allow the boot to close,
then your gonna need some 25/30 spacers to lift the lock mech
all the electrics in the boot are different
or the proper way but id send it to a body shop for
cut the saxo rear slam panel away, then weld 106 one in