First off, the hardware in question:
Sony Xperia Z
I've investigated a lot of threads here and elsewhere and watched through some videos, but no solid method of rooting it as yet.
So far, I've:
1) Gone into the developer settings and checked the bootloader status. It is set at Bootloader unlock allowed: no
2) I contacted my carrier and had the phone unlocked so that it is SIM-free. I have tested this and can now use any SIM card. When I recheck the developer settings however, it still says Bootloader unlock allowed: no.
3) I've used Sony's own unlocking site to run through the various settings and to upload my IMEI. I have a unlock boot loader key from Sony, but still cannot get this damn bootloader to say anything other than 'no'.
4) Reasoning that it might just be falsely reporting its status, I tried using the unlock function within Flashtool and it bugs out with a "Bootloader not unlocked" message.
So, as a last resort, I'm turning to you guys. Is there anything, short of me asking Sony or making hardware changes myself, I can do to get this damn phone rooted?