HYUNDAI is expanding its high performance line up and we have just driven the next model to come in the N range of cars four months before it's due for release.

The i30 Fastback N is not slated for sale before the New Year but we have already got behind the wheel of a camouflaged prototype.

And the car comes with some revisions to the i30 N hatchback on which it is based with changes to the suspension and handling to make it even more responsive.

The results were there to see on Millbrook's famous Alpine hill circuit in Bedfordshire where the i30 Fastback N showed its new prowess in accomplished fashion - and that was on a development vehicle which is still to be refined before the car enters production.

Completely camouflaged outside and with drapes, stickers and cowls over the dashboard to conceal its identity, the i30 Fastback N may have been a prototype but came fully kitted with drive mode buttons on the steering wheel and a fast-throw action to the gear changes.

It felt delightfully balanced, cornered with ease around the sharp Millbrook bends and even managed to go airborne over one of the steep rises.

It is part of growing development programme Hyundai has adopted to put its N cars in pole position when it comes to affordable performance motoring.

At £25,010 the i30 N costs just £1,100 more than a top grade regular i30 - or some £4,000 if you go for the 275bhp Performance model - and that same sort of premium can be expected for the Fastback which currently tops out at £25,160.

The new Fastback is powered by the same 2.0-litre turbo engine used in the i30 N and will be available in both 250 and 275bhp outputs with similar performance to the hatch.

That means a 0 to 60 acceleration time in the region of 6.1 seconds for the higher powered Performance version which will put the Fastback N in a place of its own as a four-door compact coupe.

The real changes are subtle but have had a marked effect on the car's handling with more feedback and even less understeer close to the limits.

The i30 N has already been described as ‘the corner rascal' because of its track-oriented characteristics which have won it many plaudits for its handling on the road and on the circuit.

But there was a feeling there was room for improvement as development engineer Sven Risch explained at the Millbrook proving ground where Hyundai brought the early i30 Fastback N at the start of a series of customer awareness days.

"We have made the springs softer at the front with thinner stability bars and the bump stops have been changed to come in earlier," said Sven. "There are also changes to the electronics to keep roll at a low level."

The Korean car maker is taking its N programme very seriously and has recently recruited Thomas Schemera from BMW to become executive vice president of its high performance vehicle and motorsport division.

Schemera joins Albert Biermann - the brains behind the N vehicles who came to Hyundai from BMW's M division - and the two oversee a growing team of engineers who have been snapped up from the likes of AMG and Bentley.

"These cars stand for pure emotion," said Schemera. "It's all about driving and the driving experience changes the minds of the customers who are now pouring into our showrooms.

"The i30 N is the most emotional car in its segment and compared to the Golf, Megane and the Honda Civic Type R it is awesome - just awesome."

He said that driving fun was a core philosophy of the N brand and that further models were already in the pipeline including a halo car that is likely to appear in the early 2020s.

Other N models may include a rival to Ford's new Fiesta ST in the shape of an i20 N while ‘hot' versions of Hyundai's line up of SUVs could be considered.

On the motorsport front Hyundai's N cars have already built a reputation competing in the World Rally Championship, touring car series events and the i30 N recently finished second in its class at the gruelling Nurburgring 24-hour endurance race.

And with the developments being made to the N cars set to make their way on to all models in Hyundai's performance division we could be about to see a new leader of the pack.