If you missed it the first time around and were not able to watch it on the BBC iPlayer, the superb Hammond meets Moss documentary will air for a second time on BBC 2 at 11.20pm on the 26th July. It covers Stirling's career briefly before going onto to look at the accident at Goodwood in 1962, which removed him from the top flight of motorsport that he loved so much.

Despite eventually making a full recovery, he chose never to race again at the highest level. As Stirling says to Richard Hammond, during a poignant piece in the programme, “I felt lost”, for him the difference following the crash was that “instead of doing things automatically, as I always had, I had to think my way around the track”.This all-important edge for the professional racing driver, between the brain's automatic and conscious processes, is the key message of the show.

Hammond's own brush with death came in 2006 following a 288mph crash in a jet powered Vampire dragster for the show, Top Gear. He spent two days in a coma and woke up utterly confused. "Your perception of everything goes on in your head," he said. "I lost the ability to cope with nerves and I was in a terrible mess”. They go onto compare the experiences of their crashes before, during and after, focusing on the recovery process following brain injury.

The documentary is harrowing at times, at others funny, and features interviews with Professor Sid Watkins, leading neurosurgeons as well as with Hammond's wife Mindy and for the first time ever, an interview with Val Pirie, Stirling’s PA known as “Viper”, who looked after him following his accident. Throughout the programme there is a serious scientific message, with head injuries effecting more than 1 million people in the United Kingdom, that the pair's experiences with this form of trauma bring to life