Aston Martin debuted its new limited-edition, track-only Vulcan supercar at the recent Geneva International Motor Show. With an all-carbon-fiber monocoque and body and motorsport-inspired lines, the Vulcan’s design language may signal what is to come for Aston Martin’s next road-ready supercar (and the potential successor to the $2 million Aston Martin One-77). The British carmaker says the Vulcan’s 7-liter V-12 engine will deliver more than 800 hp to the rear wheels, making it the company’s most powerful…