Whilst many think the future of personal powered transport lies in pure electric, hydrogen fuel cell, or number of non-carbon burning devices, VW thinks there's life in the oil based internal combustion yet. With the potential to travel 100kms on 1litre of fuel (280mpg), the XL1 profers a pretty good defence. Super light, super aero, and highly efficient the XL1 uses a diesel electric hybrid drivetrain to hit its amazing targets. It really works, and they're really thinking of building it - although only 250 examples. Dear Prius, you are officially out of date...