I found this document on the net, it relates to "frontal impact compliance" of Subaru vehicles in New Zealand.
http://www.keystonecars.co.nz/document/Subaru.pdf
The part I find interesting is that, for the SVX, only chassis numbers later than CXW5001 are compliant. This suggests (to me) that a safety improvement was made at this point during the manufacture.
I wonder what they changed.