Subaru has been building the current-generation WRX for five years and has introduced a plethora of special, limited-edition versions in different markets , including Japan and the U.S.
Despite all of this, it still hasn't launched a proper STI model.
Could this mystery prototype offer a glimpse of the long-awaited STI, or will it be another package that leaves Subaru fans feeling underwhelmed?
Stay updated with continuous reporting from Carscoops.