Start-up Faraday Future has unveiled a self-driving electric car that it says can accelerate from zero to 60mph (97km/h) in 2.39 seconds. Faraday says the FF91 accelerates faster than Tesla’s Model S or any other electric car in production. It was shown off at the CES tech show in Las Vegas. But Faraday Future has faced financial difficulties and one analyst said it had to challenge “scepticism” following last year’s CES presentation. The FF91 was