Subaru (UK) Limited introduced two new WRX STI models at the British Auto Show that have specific tuning by Prodrive. The first is WRX STI 330S, intended to compete with the UK-spec Lancer Evolution X FQ-330. It produces 330 PS (243 kW; 325 bhp) and has a 0-60 mph time of 4.4 seconds. The last of the two would be the WRX STI 380S. It could make it into production within 6 months, pending positive consumer reception. It sports new wheels and an upgraded body kit. It is expected to produce 380 PS (279 kW; 375 bhp). Currently, there are no other specs for the car. Subaru announced, on September 10, 2008, that the 380S variation will not be produced, due to homologation and specification difficulties. The regular model is called WRX STI Type UK.

2010 Subaru Impreza WRX STI with optional BBS wheelsThe Singaporean, Indonesian, and Australian (all RHD countries) markets received the 2.5 liter Euro-spec version instead of the J-spec version, producing 296 horsepower (221 kW) and 407 N·m (300 lb·ft) of torque.[20] Some of Impreza WRX STI’s sold in Indonesia are the 2.0 liter JDM spec brought by the general importers before Subaru officially introduced the 2.5 liter model. In Australia the regular WRX STI is sold alongside the WRX STI spec.R which comes with BBS wheels and Recaro seats.