Well Nissan UK have officially come back with the information that my car was manufactured after the fault was discovered and rectified, therefore not needing a replacement part.
Forgive me for being sceptical, but my vin is lower than 0300691, so I have my doubts as to the validity of this comment!
However, do the roadster vin run concurrently with the GT models or do they have a different number system?
Also how easy is it to drop the interior trim to see which lock is under the steering column?