Infiniti has revealed further details of a four-seat fastback concept that previews a future rival to the Porsche Panamera. The Infiniti Q80 Inspiration will be revealed in full at the Paris motor show next month.

The concept – plans for which were exclusively revealed by Autocar a year ago – is described as a "low-slung, ingeniously aggressive four-passenger fastback" and previews a production car which will sit at the very top of Infiniti's range.

Infiniti's long-held plans to take on luxury rivals like Porsche with a larger sports saloon are well known. It's previously been mooted that such a car could come to market in 2017 or 2018. However, there is also a possibility that the Q80 Inspiration will instead inspire a more luxurious saloon to rival the Mercedes-Benz S-class.

The company's executive design director, Alfonso Albaisa, told Autocar: "This is a portfolio extension and it shows what it means for Infiniti to go to the upper premium segment.

"We want to create a new silhouette and also show that tailoring is the key to Infiniti’s future. Inside there’s no compromise on the emotion or the roominess, that’s why it’s a five-metre car."

According to the Japanese manufacturer, the Q80 Inspiration "provides a glimpse into Infiniti's high-performance and efficient hybrid-electric powertrain implementation".

The Q80 Inspiration is 5052mm in length with a wheelbase of 3103mm. It is 2027mm wide, 1350mm high and rides on 22in alloys.

As a comparison, the production Porsche Panamera is 5015mm long, 1931mm wide, 1418mm high and has a wheelbase of 2920mm.

As with many contemporary concepts, the Q80 Inspiration does away with wing mirrors to retain the sleek side profile. There's also a teardrop-shaped passenger greenhouse, and the doors open in what Infiniti calls a 'portal' style – what some would call a 'suicide' door arrangement.

Although Infiniti hasn't revealed any images of the cabin, it describes it as having a '1+1+1+1' seating arrangement – in other words, four individual seats – and the occupants are surrounded by premium materials including carbonfibre, aluminium and leather.

The chassis is light and rigid, combining lightweight acoustic glass and additional sound deadening materials to provide a extremely hushed driving experience. Infiniti says the car would utilise advanced adaptive suspension for a cosseting ride.

Infiniti said the Q80 Inspiration is a design to which the company's four worldwide design studios "will refer regularly" when creating future production models.

Simon Cox, boss of Infiniti's new London design studio, added: "The Q80 really is something unique. It has a distinct feeling, especially when compared to our German rivals. We want to be provocative, we want to be different but desirable."

The  Q80 Inspiration will take some of its styling cues from the firm's Essence concept of 2009.

The production version that follows will form part of the brand's plan to grow its range and thoroughly overhaul its existing line-up.

The brand's current UK range comprises the Q50 and Q70 saloons, the Q60 coupé and convertible, plus the QX50 and QX70 sports-utility vehicles.

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