"There's no denying it will be a real challenge for us," Harris says. "But there's less of us to damage so we're a lot harder to injure. In all seriousness though, seconds count in motorsport but it's a sport where nobody cares if you're disabled or not. In fact, you're positively encouraged to use the latest technology, whether on your car or on your prosthetics, to get the best result."
A case in point for Harris, who lost his left leg below the knee after an infection from an IED blast, was the clutch on his Wildcat. He was unable to feel the biting point until the team's mechanics fitted a warning light system to let him know when the pedal was depressed.
An even greater challenge faces Neathway who lost both legs above the knee and his left arm after triggering a booby-trapped sandbag in Helmand Province in 2008.
"My prosthetics are not built to withstand the condition on the rally, by which I mean shocks, knocks and extremes of temperature," he says. "They're meant to last about five years in normal conditions, but with all the punishment I'm putting them through, mine will probably only survive two years."
He's taking two spare sets of legs with him to South America and, like the other above-knee amputees, will need to make sure his limbs are free of sand and fully charged from his car's on-board power supply.
"The real challenge for the Race2Recovery team will be the South American sand," says Chris Evans, a Dakar veteran who helps organise the event and has followed the team's progress in training and at the Tuareg rally in Morocco. "The sand is soft and it'll be really tough if they get stuck and need to dig out one of their vehicles in the searing heat ... That beats many people who are fully able."
Martin Colclough, head of sports recovery at Help For Heroes, agrees the Dakar will be a new challenge for the team. "Modern prosthetics are very robust," he says. "But the conditions on Dakar will test the team's limbs to the limit because, as with all modern technology, sometimes prosthetics trade off robustness with function."
He says Neathway faces the most difficulties: "The drivers mainly have below-knee amputations so fairly simple prosthetics they can maintain with their personal pack of Allen keys, grease, oil and grub screw. But for amputees with more complex needs like Tom, the biggest risks are the kinds of shocks they'll experience over rough terrain and extremes of temperature."
All the drivers and navigators are also likely to face exhaustion and pain related to their amputation sites during the rally. Limbs removed surgically, in the treatment of cancer for example, tend to have very clean stumps, but limbs lost in combat are often irregular and can still have embedded shrapnel. Socket technology is advancing and organisations like Help For Heroes and British Limbless Ex-Service Men's Association are working on therapies, while researchers at MIT in Boston are working on biomechatronic limb sockets, but it will still be a major area of concern for the team.
"Their sockets are made of carbon-fibre material and shock loading on those can result in cracking and discomfort. There's also the risk of fungal infection to worry about, so the guys need to be meticulous about caring for their stumps" Colclough says.
As well as raising more than £1 million ($1.94 million) for Tedworth House, one of five recovery centres set up with the Ministry of Defence, Help for Heroes and the Royal British Legion, the team are working to rebuild themselves for the future in line with its tagline "beyond injury, achieving the extraordinary".
And it's not the only amazing thing Race2Recovery could achieve. "All the mechanical equipment, from their Land Rover engines to their sockets and prosthetic limbs, will be tested to the limit out there, so we'll get excellent feedback for the development of future technology and sports rehabilitation," says Colclough.
The Dakar Rally
What: 15-day endurance race
Distance: 8000km
Covers: Peru, Argentina and Chile
Background: Shifted to South America from West Africa in 2009 because of terrorism fears
- Independent