Details have emerged of special lightweight and highly adjustable seats that will be fitted to the next, and fastest ever Vauxhall Astra VXR.

Using a 2-3mm-thick injection moulded polyamide and fibreglass sheet inside the seat shell means that all the necessary strength is maintained, but the seats are up to 45% lighter than conventional units.

Slimmer, too, so the seats can be mounted 40mm lower than in a normal Astra hatchback, and even 17mm lower than in the Astra GTC coupe.

Depending on specification, the new seats can also be adjusted 18 ways - previously unheard-of in this class of car. There's up, down, forwards and backwards, seat back angle forwards and backwards, seat cushion angle more or less steep, seat cushion longer or shorter, four-way lumbar support adjustment and four adjustable side bolsters to hug the driver perfectly.

In theory, there should be no one of a reasonable height who can't get comfortable in the Astra VXR, providing there's enough adjustment in the steering column.

In fact, the seats have been certified by an independent German organisation called AGR (Action for Healthy Backs in English), which comprises a number of apparently leading doctors and therapists.

The Astra VXR will be officially unveiled in the flesh at the Geneva Motor Show in March. It will feature a mechanical limited-slip differential, tricked-up suspension and Brembo brakes.

Its 276bhp and 295lb.ft are a little way short of the Ford Focus RS's figures, but the Astra is set to be lighter and, in all likelihood, even more of a handful. Pricing and on-sale dates are to be confirmed very soon.