Inhabitat's Week in Green: Flying cars and an urban underground park

Plus, spin classes could help you power through the laundry.

The Tesla Model X is the best car in its class - but it's also prohibitively expensive with a MSRP of $83,000. That's set to change, as Tesla just launched a new version of its electric SUV that is $9,000 cheaper. If you're holding out for a flying car, you won't have to wait much longer - Aeromobile just unveiled a brand new prototype and announced plans to launch a commercial flying vehicle by 2017. The European Space Agency backed a new hypersonic plane that will be able to travel from London to Sydney in four hours flat. And a Welsh company created a truck that carries its own road surface, lays it down, and then picks it back up.

It's official: New York City just gave the green light to the world's first underground park. The Lowline will be built in an abandoned train line in the Lower East Side, and it'll feature high-tech daylighting system that uses mirrors and fiber optics to sustain an underground forest. In other news, a team from MIT has developed a transforming "apartment in a box" - and they're planning to bring it to market in 2017. Google's plans for a crazy canopied headquarters were quashed last year, but thanks to a new deal with LinkedIn the project will actually be built.

Love coffee and mushrooms? Check out this new coffee maker that uses old grounds to grow tasty fungi. In other design news, we spotted an amazing conductive pen that lets you turn simple sheets of paper into electric circuits. A 14-year-old girl used old bike parts to invent a brilliant pedal-powered washing machine</a> that saves time and energy. Olive launched a smart suitcase that automatically follows you around so you don't have to lug luggage. And researchers used bacteria to develop microscopic "wind farms" that could one day power your smartphone.