Hi,
I run a website which specialises in collecting certain Nissan's production (colour/date/model code/type etc) information and working out build numbers etc.
I decided to take a look at the 22B to see what I could find and here is a list of 430 VIN which have the model code of GC8E2SD (for 22B).
List can be found here: http://gtr-registry.com/en-subaru-wrx-sti-22b.php
I checked 1 of the Australian VIN (JF1GM9KD3WG071730) and the last 6 digits lines up with GC8-071730 which is right near the end of production. I also checked 3 other Japanese 22B VIN and they all matched.
Cheers.