THE latest incarnation of the fast Subaru may be more refined these days than the old Scooby beloved of rally fans but it is still fast, furious and and not for the faint hearted.

The definitive WRX STI emerged in 2001 and soon became a byword for performance and the current model, which has dropped the old Impreza name incorporates a wide range of developments which maintain the evolution of this iconic vehicle without destroying the old wild child character of the car.

And in response to significant market demand the four-door saloon version of the Subaru WRX STI 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.

Extensive testing under a wide variety of weather, traffic and road conditions, and extreme ‘hot laps' around famous racing circuits have honed this car into something of a must-have experience for performance fans.

Retaining the old horizontally opposed boxer engine which now features an enhanced burble to its beat the car can shoot to 62mph in a jaw-dropping 5.2 seconds and carry on to a maximum of 158mph.

Road-holding is razor sharp courtesy of a stiffened bodyshell and an extensively reworked suspension system - based upon the marque's widely praised ‘spec. C' set-up. Lower ride height and wider tyres also contribute to more direct and accurate control of the car and greater feedback for the driver.

Increased suspension travel allied to the new set up helps both road-holding and ride refinement. Yes, it does feel more civilised but is no less exciting because it gives the impression that it is far more capable of the extremes that may be demanded of it.

Inside, the car does indicate that it needs a little more imagination over interior styling, but this is made up for by the introduction of Recaro bucket seats which hold you close and snug while the latest STI struts its stuff and leaves just about everything standing at the lights.

The 2.5-litre Subaru boxer 16-valve turbo engine produces 300ps at 6,000rpm and massive torque even from low-revs. In in doing all of this it sounds absolutely beautiful.

It is still a thirsty brute with a combined mpg figure of 26.9mpg and it is cleaner - successfully meeting Euro5 exhaust emissions standards with a CO2 emissions readout of 243g/km.

At the heart of the Subaru handling success story is the company's legendary Symmetrical AWD (All-Wheel drive) system. This combines the intrinsic low centre of gravity of the boxer engine , combined with advanced AWD technology incorporating sophisticated front, centre and rear differentials. For the latest WRX STI the system is uprated, with revised settings for the differentials.

All in all this is a much more refined but nonetheless thrilling driving experience as can be expected from Subaru.