The Grand Tour: Jeremy Clarkson, James May and Richard Hammond are back on the road

But it’s not over til it’s over. The penultimate episode of the Amazon Prime series, The Grand Tour: Sand Job, sees the trio race across the wild and arid stretches of Mauritania in north-western Africa.

Rumbling along the tracks of the legendary Paris-Dakar rally, across the undulating dunes of the Sahara Desert, treacherous river crossings and steep ravines, their trusty steeds are not bespoke Dakar racers but cheap modified second-hand sports cars.

“I love deserts so I’ve always wanted to do the Sahara,” Clarkson, 63, says of the road trip. “And then it was really a question of finding the most inappropriate cars for trans-Sahara travel, and I think we did a pretty good job on that.”

“We actually all quite like being in the desert,” adds May, 61. “We like the dust and the sand and the heat. It’s exhausting but it’s all the things that TE Lawrence talked about – he said ‘the desert cleans you and it’s pure’ and I think that’s true. We all slightly get off on that and feel like we’re being really heroic and manly.”

The three picked different sports cars for the adventure, to varying levels of success. Clarkson opted for a Jaguar F Type V6, Hammond an Aston Martin Volante V12 and May an Italian Maserati.

He was so impressed by the Jaguar, Clarkson bought one as soon as he got back home. “And I don’t think Hammond bought an Aston Martin afterwards,” he jibes. “The other two made unwise choices as usual. The Jaguar was so tough and unbreakable… I cannot lavish enough praise on that car. I brought back the one I drove in Mauritania too – have it at the farm.

“Hammond in particular had constant issues. It started off being funny and then it became annoying because it was relentlessly unreliable.”

“There was the odd issue,” admits Hammond, 54. “It turns out an elderly V12 engine isn’t the best place to start when you want a rugged machine for crossing deserts. A Toyota Landcruiser is where people ordinarily go, not a hand-built, British-engineered, luxury GT. I did ask quite a lot of my car.

“The problem with my car is that it came from an era where the whole idea of computers running the show was taking hold. So cars were becoming clever but mine hadn’t become quite clever enough. It would have been better to have had something earlier or later. Mine was exactly the wrong period, when it thought it was clever, but it wasn’t.”

For May, it was refreshing not being the one left behind. “It was long overdue,” he says. “I’ve been left behind in quite a few other things due to poor choices. So it was quite gratifying and also slightly surprising because of all those cars you’d expect the Maserati to be the unreliable one; they do have a bit of a reputation for fragility.”

Camping in the desert hit differently for Clarkson and Hammond.

Calling himself a “boy scout,” Hammond says he relished the quiet nights in his tent. “I’m never happier than when I’m packing my bag and I’m wrapping up my best pen knife and a collapsible stove and a little bag to put things in to keep them dry,” he elaborates. “I like a sleeping bag and a torch. I love all things to do with camping… There were evenings when it was quieter and things were smaller, and I was in my funny little tent on my car on my own and I’m very, very happy doing that. ”

Clarkson, on the other hand, was not so camping-inclined. Neither was May, who described it as “awful”. “Camping is always ghastly,” Clarkson says. “But when you’re in the middle of the Sahara Desert, you have no alternative. There are no hotels, there are no guest houses or even restaurants or shops. It’s very much the opposite of, say, Luxembourg.”

And the blistering heat was another challenge. “It was bloody tough,” Clarkson admits. “We drank litres and litres of water and we didn’t pee. I mean, I don’t know where it was going. Hammond said after three or four days, ‘I’m going to have a pee’ and I suddenly thought ‘I haven’t had a pee this whole time.’”

Despite the desert heat, tent accommodation and endless Hammond breakdowns, the road trip holds a special place in the presenters’ hearts.

“This special treads that path that we’ve travelled very carefully,” says Hammond, “which is that you don’t have to be a car nerd to watch the show because we do that for you. That’s been our motto, spoken and unspoken, for all the years we’ve done it because it’s in our blood, it’s in our hearts – and you can see it.”

“It was honestly hilarious,” continues Clarkson. “Hammond’s Aston endlessly breaking down was very funny.

“Listen, when we do these things, it is a laugh from start to finish. We know what we’re doing and we do enjoy one another’s company. Otherwise, we wouldn’t have been doing it for 25 years. It was tremendous. It was a big laugh.”

“When we started the journey, I think we all wondered if it was going to be a little bit too difficult for the cars that we’d chosen,” May relates. “We do tend to be a bit optimistic and we tend to push complications to one side and hope that somebody will deal with them.

“So I was quite pleased that it ended up being a good adventure. It’s a very long special because there’s a lot of material. We always tell ourselves we don’t actually need to do 1,200 miles or whatever, because we have enough adventure in 200 miles to make it special. But we still go back and do 1,200 miles because either we like it or we’re a bit stupid.”

The Grand Tour: Sand Job comes to Prime Video on Friday February 16.