First pictures of new Tramontana XTR

We're not sure if this is (a) a schoolboy fantasy come to life, (b) a high-performance aerobatic aeroplane without wings, (c) the ultimate go-kart or (d) completely over the top*, but this, according to Spanish bespoke supercar builder Tramontana, is the successor to their aptly-named R model, the XTR.

Bespoke, Cyril, means that you pay for it in full first and then argue with them over exactly what you are going to get for your money.

In this case, the chassis of the XTR has been stretched to accommodate two occupants - sitting in tandem under a transparent canopy as in a high-performance aircraft - in place of the open solo cockpit of the R, with appropriate suspension upgrades.

The bodywork, such as it is, has been restyled.

The changes are mostly cosmetic, other than a better diffuser, new front splitter and more powerful headlights.

The whole thing weighs less than 1400kg, including a 5.5-litre, twin-turbo, AMG V12 that's been tweaked by Tramontana to deliver a quoted 662kW and 980Nm to the back wheels via what it describes only as “an ultra-rapid competition gearbox”.

Performance, as our New World cousins are wont to say, will be awesome: 0-100 in an estimated 3.6 seconds and a top end of about 344km/h.

Prices start at €420 000 (R4.25 million) ex works and deliveries are expected to start in the fourth quarter 2012.

*It's all of the above, actually.