Por lo visto ya aparecio en el salon de Detroit... Remember the ASC Diamondback Viper concept car at the Detroit Motor Show last January? It looks as if that was an ongoing project, as a number of these Vipers have now been spotted out road-testing in Colorado. The American Specialty Cars (ASC) consultancy worked on the Viper SRT-10 for Chrysler and then produced the Diamondback, tuned and accessorised by McLaren Performance Technologies. Like the Detroit show car, the red prototype seen here has a carbon fibre composite bonnet with air intakes, as well as composite roof, rear deck lid and other components to save weight. The V10 engine in the concept car was said to develop 615bhp, but rumours suggest that the road-going model will give as much as 650bhp - a 0-60mph time of under 3.5 seconds has been posited. The 'standard' SRT-10 delivers a mere 500bhp from its 8.3-litre engine and 0-60 in 3.9 seconds, so a car some 85lbs lighter and breathed on by McLaren has to be very seriously fast indeed.