Stephen Sackur speaks to Sir Ron Dennis, founder of the McLaren Group and one of the most successful team leaders ever in Formula 1 racing. He was known as a technical innovator and perfectionist focused on marginal gains in every aspect of race car design. Sir Ron and his McLaren team won a host of F1 constructors' and drivers' world championships with some of greats of motor racing: Niki Lauda, Alain Prost, Ayrton Senna and Lewis Hamilton. What fuelled his drive to win?