A cross between a skateboard and a hovercraft, hoverboards were the kids’ version of the flying cars in BTTF 2 . There’s no hope at all that Mattel or anyone else will release a working hoverboard in 2015, but it’s possible they could be a reality at some point in the not-too-distant future. Various theories about how the producers made hoverboards work for the film were bandied about, including hidden magnets. The reality, however, is much more mundane. The actors were suspended on wires that were removed in post-production, and the hoverboards stuck to their feet.