While dealers will get the first five-door Imprezas late this summer, the performance STi won't debut until October's Tokyo Motor Show. As a result, customers will have to make do with the entry-level car until the flagship arrives in 2008. The STi is powered by a tuned version of the 2.5-litre boxer engine, turbocharged to produce more than 300bhp and around 400Nm of torque.

It will be mated to Subaru's existing six-speed manual 'box, while a new automated manual, sourced from specialist firm Aisin, is expected to join the line-up when the latest Impreza is facelifted in 2009. That will ensure the hot STI can compete with its arch-rival, the Mitsubishi Evo X, which will get a paddleshift gearbox when it debuts next spring.

The top Impreza gets a range of unique styling additions, including a specially developed bonnet, grille and a wide front bumper with big air intakes. Flared wheelarches house smart 18-inch alloys, which will hide the existing STi's Brembo brake system. Buyers can expect to see minor tweaks to the all-wheel-drive system, and engineers have also taken the opportunity to tune the handling, thanks to a more compact double wishbone rear suspension set-up. Inside, the new Impreza range benefits from higher-quality trim, and the STi will also get a pair of supportive bucket seats up front to boost its sporty appeal.