But finance proved the stumbling block. The local track closed, and the nearest alternative was across the border in Bristol, southwest England, about 70km away.
"I stopped when I was 11," said Jann, "because it got too expensive."
He returned to his bedroom, where he took to the next best thing - virtual racing on the video game Gran Turismo. It was the perfect release for the racing-obsessed teen: a singular pursuit offering a test of individual skill in which he could lose himself.
"One day," said Steve, "he came downstairs and said, 'Dad, I've qualified.' I said: 'Qualified for what?"'
In the middle of last year, Jann, then 19, entered an online competition on Gran Turismo 5 that offered a shot at the real thing.
Out of 90,000 other virtual racers, he made it into the top eight in Europe and won the chance to test himself against other gamers in a real car at Brands Hatch racing track near London. That he had kept it to himself for so long was entirely in character for a boy who did not like to make a fuss.
"At that point we had no idea what it was," admitted Steve.
Seven months later, in January this year, Jann, who'd never set foot in a racing car, was at the wheel of a serious piece of kit in the Dubai 24 Hour race - and at the beginning of what appears to be a very exciting career.
The video-game franchise in which Jann began his journey, Sony's Gran Turismo, was originally designed by Japan's Kazunori Yamauchi in 1997.
Gran Turismo stood out for its quest to mirror a physical rather than fantastical reality. This was a racing "simulator" and its success (more than 60 million sales worldwide) owed everything to how well it measures up to the real thing.
Its sports cars may be virtual creations, yet everything about them was designed to behave as closely as possible to the genuine article.
The level of accuracy now available in computer modelling meant Formula One drivers, as a matter of course, do laps on simulators in preparation for races. Lewis Hamilton himself admitted to learning tracks during his rookie F1 year playing PlayStation with his brother.
Sensing a marketing opportunity, Sony teamed up with Nissan to form the GT Academy in 2008. It was a one-off project created to answer a simple question: could you take a gamer and put them in a real racing car?
A 23-year-old Spaniard, Lucas Ordonez, won the online and then real-world challenge. After intensive training, he raced as one of a team of drivers in the 2009 Dubai 24.
The programme was extended to see if this unorthodox method could uncover further talent. French gamer Jordan Tresson won a GT Academy place in 2010 and Ordonez himself went on to race for the professional Signature Nissan team, taking a podium at sports car racing's most important meeting, the Le Mans 24 Hours, last year.
From this came the concept of a car driven only by computer gamers entering this year's Dubai 24.
Two new candidates were needed to be brought up to speed and the academy opened its online competition again. Which was how Jann found it.
The transition from computer-generated racing to hard, cold, dangerous steel ought to be difficult yet for Jann it was instinctive: "It felt completely normal," he said.
How to read racing lines - correct entrances and exits to corners; hand-eye co-ordination and a visual sense, plus the ability to look ahead of the car into breaking zones, had all been learned in the bedroom.
He passed the test at Brands Hatch and later, at Silverstone, beat 11 other finalists to the place as a GT Academy driver.
"My mouth was hurting because I was grinning from ear to ear so much," Jann said.
He was placed on a driver-development programme at Silverstone and in six months he and the winner of the US GT Academy, Bryan Heitkotter, gained their international racing licences, a process that normally takes three years.
The gamers were young, malleable and without ego. Even the lack of racing experience had a positive side-effect. Jann's mentor Rob Jenkinson, a former racer himself, was sceptical of the academy concept but became convinced after seeing it in action.
He said that drivers entering through the traditional route have longer to pick up bad habits, sometimes taking years to correct. "With this, in six months we eliminate mistakes," he said. "We make good decisions on their behalf immediately."
What cannot be eliminated is the danger. Accidents now mean more than just hitting the restart button.
"I know there's a dangerous side to it, but it didn't really cross my mind," said Jann, despite having rolled the car at a race in Holland.
In Dubai, at the MotorCity circuit, Jann is ready for the 24 Hour race. He shares with Hamilton not only the sculpted good looks but the calm self-assurance the McLaren driver displays.
There's no sign of the shy teenager. Motor racing is all about focus, and before he stepped into the car Mardenborough had it in spades.
For the first part of the race, the crew and drivers were struggling with mechanical gremlins.
Each team raced flat-out stints interspersed with furiously quick pit stops, looking to eke out tiny advantages that over a full 24 hours can make the difference.
With an hour and a half to go, one driving stint remained and in third place, Neville chose Jann to take the wheel. Having raced so hard for so long, a mistake at this stage would be heartbreaking. The pressure was immense. But Jann brought the car home with ease and the team made the podium.
"When I was 17 or so I was afraid to answer the phone," he said, "I've come a huge, long way."
His mother calls it a "fairy story". Just over two weeks after the race Nissan confirmed Jann as its fulltime driver for the season in the Blancpain Endurance Series - a full-scale, six-race, professional racing competition that visits some of the most famous circuits in Europe. It might be the start of something great.
- The Observer
