"Maybe we'll make a flying car, just for fun," said Elon Musk. From any other businessman, such a statement would be a joke. But the billionaire, 42, who has poured the millions he made from the sale of his online payments firm PayPal into companies producing top-of-the-range electric vehicles, solar power and spacecraft, is serious.

"I've thought about it quite a lot," he continued, as cable cars drift past the plate-glass window behind him, their passengers peering out over Docklands, east London. "We could definitely make a flying car – but that's not the hard part. The hard part is, how do you make a flying car that's super safe and quiet? Because if it's a howler, you're going to make people very unhappy."

Mr Musk has a reputation for saying things that sound too good to be true – and then making them happen. Yesterday he was in London to launch the Model S, a luxury saloon car manufactured by his firm Tesla that he hopes will change British attitudes to electric cars.

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Priced between £50,000 and £100,000, and able to go from 0‑60mph in just over four seconds thanks to the massive battery unit arranged along its underbody, it is clearly not aimed at eco-conscious families on a tight budget. But sales in the United States have been good, partly because of its high range of 300 miles and partly because it drives nothing like a traditional electric vehicle.

"It was very important to create a car that won on the merits of being a car itself – because there's a limited number of people who will suffer for the environment," said Mr Musk. "We wanted to show that it was possible for an electric car to be one of the best cars in the world. That's necessary in order to change people's minds."

Mr Musk spoke to The Independent on Sunday shortly before striding on to an outdoor stage at the Crystal eco-exhibition centre in east London to hand over the keys to the first five British owners, one of whom was EL James, the author of Fifty Shades of Grey, whom he says is an "enthusiastic" advocate of what is only Tesla's second vehicle. Watching from the wings were his wife, British actress Talulah Riley, and his children.

Within three years, he said, he wants to release a car with a similar range priced at about £25,000. But he promises there will be no compromising on performance. "We're never going to release an ugly car. We want it to look good, to feel good, to have good acceleration, handling, everything."

Mr Musk also revealed that Tesla is looking "quite seriously" at opening an engineering research and development centre in the UK, probably in the Midlands, as early as next year. "To attract top [engineering] talent it's got to be something significant and involved in core vehicle development," he said, adding that it should create at least a few hundred jobs. He has yet to let the Government know of his plans.

Mr Musk said he wants the UK to be covered with Tesla "supercharger" points – which can replenish car batteries in a little over half an hour – in the space of 18 months, although critics say this is wildly unrealistic.

Tesla's sudden emergence on the British electric car scene has already ruffled a few feathers. Last month, Dale Vince, head of renewable energy firm Ecotricity, accused Mr Musk's company of trying to muscle in on its Electric Highway network of charging stations, saying the company's behaviour amounted to a "smash and grab raid".

This week the dispute will reach the High Court in the form of an injunction hearing, but Mr Musk dismisses the row with a wave of his hand. "I've never even met the guy," he says of Mr Vince. "Initially when we tried working with him he started making all sorts of outrageous demands, so we thought, 'Well, OK, we'll just not work with you' – and then he sued us."

Mr Musk's other companies are SolarCity, the largest provider of solar power systems in the US, and SpaceX, which makes space vehicles and in 2012 became the first commercial firm to launch and dock a vehicle to the International Space Station. He has spoken of his desire to send humans to colonise Mars, for which he has been mocked, but he is quietly defiant of those who doubt his ambitions. "I say something, and then it usually happens. Maybe not on schedule, but it usually happens."

Owning such a technologically powerful array of companies – and the fact that he is worth an estimated $12bn (£7bn) – means he is able to pursue his pet projects. Last year he bought the aquatic Lotus Esprit driven by Roger Moore in The Spy Who Loved Me for £550,000, and is now turning a boyhood fantasy into reality. "We will be making a submarine car. It can transition from being a submarine to a car that drives up on the beach. Maybe we'll make two or three, but it wouldn't be more than that. It's not like we'd sell it, because I think the market for submarine cars is quite small," he chuckled.

It is not hard to see why the creators of the Iron Man films used Mr Musk as the basis for Tony Stark, the billionaire playboy, industrialist and engineer who creates a flying jetsuit. Whether he is a superhero or a wannabe James Bond, one thing is certain: Elon Musk works very hard, and he's showing no sign of slowing down.

Test driving the future

Not many test drives start from inside a gleamingly white, smoothly contoured interior of the Westfield White City shopping centre, but Tesla isn't an ordinary car manufacturer. And the Model S isn't an ordinary saloon. It's set to transform the way we get from place to place and how we treat the planet.

At least that's the hype. The more sceptical might point out that a car costing £50,000-£100,000 and sold around the corner from a Louis Vuitton store will struggle to be a green car for the masses. It's a view reinforced by the first Tesla customer I meet on my way to pick up the car keys. He's a former head of a F1 team who already owns a fleet of high-performance cars. No matter how green, an emission-free Model S won't do much to bring down his household emissions.

Nonetheless, the Model S is a truly revolutionary car. Until now, most electric cars only offered a range of about 100 miles before recharging, but its unique battery pack containing over 7,000 cells means the Model S has practically trebled that distance.

Plus, it's a proper saloon with space for five adults, all the creature comforts you want, and the ability to recharge via one of Tesla's supercharging stations in just 30 minutes.

It's the same story on the road, where the Model S is just as refined, if not more comfortable, than a top-of-the-range Mercedes or Audi, with terrifyingly immediate acceleration.

Buttons are few and far between and it feels a bit like driving a smartphone. It's so modern that there's not even a handbrake or start button. The car just knows the key is on board – you simply pull the column-mounted transmission down and go.

Yet, despite all this future-heavy stuff, you still have to plug it in at the mains and, in Britain, most juice is far from climate change-friendly.

Jamie Merrill