The day you have been dreaming of ever since Back to the Future II hit the big screen in 1989 has finally arrived. Engineers at Japanese car company Lexus have been working with experts in super-conductive technology to create one of the most advanced hoverboards the world has ever seen.The hoverboard uses magnetic levitation with liquid nitrogen-cooled superconductors and permanent magnets to give the hoverboard "frictionless movement" of a kind that had been thought impossible, according to Lexus."It's the perfect example of the amazing things that can be achieved when you combine technology, design and imagination," said Mark Templin, executive vice-president of Lexus International.The hoverboard is the latest project in Lexus's Amazing in Motion campaign, which aims to demonstrate the company's commitment to pursuing new possibilities in advanced design and technology.The hoverboard shares design cues with Lexus cars, including the signature spindle grille. It has also been made using some of the same materials - both hi-tech and natural - such as bamboo.The prototype is being tested in Barcelona in the coming weeks. The sad news is the Lexus Hoverboard is only a prototype, so it will not be for sale.This is not the first time engineers have tried to bring Marty McFly's gravity-defying vehicle to life. Last year a company called Arx Pax in California launched a Kickstarter campaign to create what it claimed was the world's first "real" hoverboard.The so-called Hendo hoverboard floats 1.25cm above the ground and is capable of supporting a 113kg rider thanks to electromagnets attached to the base of the board that repel any non-ferrous conductive surface.Professional skateboarder Tony Hawk has tested a prototype of the Hendo hoverboard and given it his seal of approval.This week British company Malloy Aeronautics struck a deal with the US Department of Defence to build the first truly functional "hoverbike" in the US. ..