For the boot floor part /arch, it's fab , the inner arch it's self maybe find another micra and chop it out and weld in,
It's a common place for the to for as the dirt ect gets behind the undersea L and rots the car out, find the same aboive the back box, inner sils, rear crossmber , behind the fuel filler , chassis legs ,
But as far as I've seen its only really external panels you can get , rest is find a donor or tab