Like their erstwhile boy racer owners, high performance cars eventually grow up. That’s certainly the way it is with Subaru’s iconic WRX STI.

Brilliant when it came to handling and performance, earlier incarnations felt a bit flimsy and had outdated instruments and controls. Put simply, they lacked a feel of quality. They were tin boxes – very quick tin boxes, but tin boxes all the same.

Now, though, there’s a reassuring solidity. Doors go clunk, bodywork seems carved from the solid.

So synonymous with automotive exhilaration have the six letters WRX STI become that the previous Impreza name tag has been dropped and the new car is called simply the WRX STI.

In response to significant market demand, the four-door saloon version is once again available, after an absence of three years. The hatchback variant will remain on sale, and this will consequently mark the first time that four- and five-door versions of the car have been sold alongside one another in the UK.

In order to refine its all-round performance, the 2011 WRX STI has been extensively tested under a wide variety of weather, traffic and road conditions, ranging from slow, congested city driving and rapid B-road sprints, to extreme ‘hot laps’ around famous racing circuits – including the notorious Nordschleife at the Nürburgring in Germany.

The bodyshell has been stiffened and there’s an extensively reworked suspension system. Lower ride height and wider tyres also contribute to more direct and accurate control of the car and greater feedback for the driver.

The more rigid bodyshell has also made it possible to increase suspension travel, benefiting roadholding as well as ride refinement.

Exterior styling is extensively revised, with new bumpers, enlarged rear quarter panels and lower ride height giving the car a more muscular presence. Inside, the quality of the cabin materials has been upgraded, and the driver and passenger are assured of a secure and comfortable seating position thanks to the introduction of all-new Recaro bucket seats.

The widely praised 2.5-litre Subaru boxer 16-valve turbo engine enables a zero-to-62mph sprint in just 5.2 seconds.

Significantly, the revised engine is cleaner – successfully meeting Euro 5 exhaust emissions standards.

Central to the agile handling of Subaru vehicles is the company’s acclaimed symmetrical all-wheel drive system. This consists of the horizontally-opposed boxer engine, with its intrinsic low centre of gravity, combined with advanced AWD technology incorporating sophisticated front, centre and rear differentials.

For the new WRX STI the system has been uprated, with revised settings for the differentials.

Prices start at £32,995 on the road.