It’s known to its loyal fans as the car show with a heart, bringing a tear to the eye of many a petrolhead. And while the presenters of Car S.O.S. manage to hold it together on screen for the emotional finale of each episode, when they return a secretly restored car to its surprised owner, they have confessed that they are also deeply moved.

RTS Midlands held a premiere of the first episode of series 13 followed by a Q&A, at which ebullient presenters Fuzz Townshend and Tim Shaw revealed some behind-the-scenes secrets.

Shaw admitted: “I really struggled watching that episode. I’ve only watched about three because I get too emotional. We have done 130 reveals now, and that moment when the penny drops for the owner is what we exist for.

“We don’t cry then, but I will ring Fuzz up on the way home and go, ‘You all right mate? [chokes up]. Are you crying? No, me neither.’”

The show, which returned to National Geographic on 13 March, has been running for 13 years, with previous series also screened on More 4 and Disney+. The team is based at a workshop in Walsall and, for each season, it restores 10 cars in nine months, with each project taking between 800 and 1,000 hours of hard graft from skilled experts. At what cost? “Oh, we don’t talk about money,” said Shaw. “It’s not about that. We’re not wheeler-dealers!”

Townshend, the Brummie former drummer in 1980s band Pop Will Eat Itself, said: “It’s not a car show, it’s a show about people and their love for each other. Any problems we’ve had working on the car pale into insignificance in those magical moments when we reunite it with the owner.”

“The human story comes first, the car is secondary,” series producer and director Steve Bonser told the RTS. “We have thousands of applications in our inbox and we wish we could tell more stories. They are amazing. We’ve heard of cases where people weren’t expected to live much longer – but then they carry on because the car gives them something to live for.”

One of the most memorable episodes was in series six when Gary Horne, the owner of a Lancia Delta, died unexpectedly of heart failure mid-restoration, before the car could be returned.

Shaw remembered: “That was the most moving episode and I struggle talking about it. We were not prepared for that and we shut down the whole production for a week because it was so shocking.”

The new series begins with “an absolutely ginormous job” as they rescue a Mazda MX5, transforming a filthy, rusty car covered in cobwebs and moss. It’s 20 years old with the body of an 80-year-old,” said Fuzz. The job is for Katey, for whom the car holds precious memories of her late sister.

It’s clear that the onscreen rapport between the presenting duo is genuine. At the RTS event, they continually made fun of each other, with Shaw announcing that it was not just a premiere but also the unveiling of a new item of clothing for his partner. “For 13 years, I’ve had to suffer Fuzz wearing his hideous leather jacket, but tonight he’s wearing a brand new one!

“Though he had to rough it up in the car park because it looked too new.”

Townshend added: “There’s no rehearsal – we just bounce off each other. For the first episode, they gave us a script but it was so wooden we threw it away. We’d never remember it anyway.”

The RTS Midlands premiere was held on 4 March at the Midlands Arts Centre in Birmingham. It was hosted by radio presenter Adrian Goldberg and produced by Jayne Rae.