All depends, i'm not to sure on newage cars but jap imports always used to come with higher specs better equipment in cabin,
I doubt the jdm wrx's will be forged normally just sti's that get goodness like that, they used to come with more power, mine for instance has a bigger turbo than the eudm foresters.
So it could be bigger turbo/ injestors different cams etc maybe 05's will be a twin scroll not to sure.
Basically the insurance companies see it's an import and ads some on for
A, different specs/more power
B, availability of spares & repair items, even though this is ****** as mine is identical in every way build wise to eudm cars so I can order just about anything from dealer or online and it will fit.
C, because every one adds jdm tax, no matter what it is