LONDON, England - VW’s radical XL1 hybrid car cruised through London on its way to the UK's 2013 Goodwood Festival of Speed.The new XL1 two-seater could be the most fuel-efficient production car in the world at 0.9 litres/100km due to its plug-in hybrid system. The car is powered by an 800cc two-cylinder 35kW turbodiesel and a 20kW electric motor and drives through a five-speed dual-clutch auto. Image galleryThe car will make Greenpeace happy and sniff at any CO2 emissions tax with a rating of only 21g/km. The XL1 can accelerate to 100km/h in 12.7sec, reach 160km/h and cover 50km in battery mode.LOWER THAN A BOXSTERThe XL1 is 3.8m long, 1.2m tall and 1.6m wide. By usual automotive standards, that's extreme; VW’s Polo has a similar length (3.9m) and width (1682mm) but is significantly taller (1.4m).Even a pure-bred sports car such as sister company Porsche’s Boxster is 129mm taller; to achieve its low fuel consumption the XL1 sports a classic "teardrop" shape. E-MIRRORSThe XL1 eschews traditional side-mirrors in favour of small cameras called e-Mirrors.The XL1 is assem bled (left-hand drive only) at VW’s Osnabruck factory in Germany, the plant that produces the Golf Cabriolet and Porsche Boxster. For now it will produce 250 XL1s, though prices have yet to be confirmed. Watch the video!Unfortunately the new XL1 won’t be headed for our shores any time soon. VW SA’s public relations manager: "There are no plans to introduce it."E-CAR RALLYVolkswagen will line up at the start of the 2013 Silvretta E-Car Rally in Austria with two innovative vehicles – its XL1 diesel hybrid and an electric e-up!. Drivers will be challenged to recover large amounts of power used on climbs through battery regeneration on subsequent descents.