After weeks of thumbnail-photo teases, the covers come off the Lamborghini Sesto Elemento, a new concept car on display tonight with other new vehicles from the Volkswagen Group as a part of the 2010 Paris auto show.

The name derives from Italian for "sixth element" on the periodic table, carbon--and the Sesto Elemento is described as "a technology demonstrator" constructed for the show to give an idea how the future of Lamborghini will include carbon-fiber construction techniques.

The heart of the concept is the powertrain found in today's 2011 Lamborghini Gallardo LP 570-4 Superleggera, a 5.2-liter V-10. In this application, it's tuned to put out 570 horsepower and 398 pound-feet of torque. As in the Gallardo, the engine's coupled to an automated manual six-speed transmission.

The stunning body of the Sesto, though, is composed almost entirely of carbon-fiber reinforced plastics, dramatically cutting the curb weight even over the aluminum body found on the Gallardo. While making the new exotic car stiff and safe, Lamborghini says in a press release that the new technology also slims down the monocoque structure to less than one metric ton, or just over 2,200 pounds.

The light body and muscular powertrain combine for a power-to-weight ration of 3.86 lb/hp, which Lamborghini predicts would slingshot the Sesto to 60 mph in under 2.5 seconds--an acceleration figure roughly equal to that of the Bugatti Veyron Grand Sport, and nearly a half-second quicker than today's Porsche 911 Turbo.

Carbon figures in the Sesto's carbon-ceramic braking system as well as its exhaust system, which is fabricated in part with the same materials.

Earlier this month, Lamborghini delivered a carbon-fiber manifesto, with CEO Stephan Winkelmann saying the brand would counter the increasing weight of its cars by redefining them through the new build technique. While Winkelmann also said his company would no longer focus on top speed as a measure of performance, it's clear the pwoer advantages of new, lightweight bodies will enable more fuel-efficient powertrains that deliver less power, but better performance, than today's Lamborghinis.

Lamborghini has placed some wagers on carbon fiber, with labs in Seattle and in its home of Sant'Agata. How quickly will it reveal its hand? The promise of a new Murcielago replacement in Paris--the Jota--seems to be dashed, but next year's Geneva motor show could hold some important clues.