OK, I have a couple of updates.
Firstly don't use hpicheck.com lol. This morning the report said "VRM not recorded by insurers as a 'total loss'. Now it states "VRM recorded by insurers as a 'total loss" and "D - Vehicle damaged but repairable - the insurer decided not to repair".
I tried another HPI check with the same result "Total Insurance Loss (Write-off)
Recorded as a Category D insurance write-off on 21 Jan 2012".
Subaru head office sent me this..."Subaru Impreza VIN
JF1GDAKD35G049971was not imported by Subaru UK Ltd it was originally sold by Subaru's representative in Malta and as such we have no record of applied registration numbers."
And finally the Subaru dealers they told me that had worked on the car previously told me that they didn't have any concerns with the car, the VIN they have registered is
JF1GDAKD35GZ049971.
The dealership told me that they did a full check and MOT in August 2013 and all was fine, they have sold it a couple of times and they have serviced it and done some minor work (Turbo gasket, air valve, radiator, engine temp sensor) all in 2013/14.
Looks like I'm going to have to keep looking! I was set on this one too.