i8 Spyder. Not the sound of a Wurzel expressing hatred for an arachnid, but BMW's roofless, two-seat hybrid concept.

It'll be unveiled at this year's Beijing auto show later this month and is, as you'd imagine, a pretty good sign that Munich's going to give us a drop-top to join the i8 coupe. For those hard of memory, that's the 250kph, 42.5kpl sportster due to land in showrooms come 2014.

The i8 Spyder concept is a little stinted compared to its coupe brother, though. Under the two-section folding roof it's slightly shorter and there's a more compact wheelbase, suggesting its original proportions - based on the splendid Vision EffecientDynamics supercar of 2009 - have been rethunk.

BMW has kept the swan doors, which swivel up like the wings of a, umm, swan... They're retained thanks to the amount of carbon that's used in the i8's super-stiff passenger ‘Life' cell, which is made from carbonfibre reinforced plastic (CFRP).

Underneath, there's an aluminium chassis with a lithium-ion battery buttered along its length, keeping the centre of gravity nice and low and achieving a 50:50 weight distribution. It's got the same plug-in powertrain as the coupe, too; a petro-electro melange of 129bhp electric motor driving the front wheels and three-cylinder turbo petrol engine sending 220bhp to the rears (that's 349bhp in all).

All together, it makes 550Nm of torque, which gets it from 0-100kph in 5.0 seconds and a tethered top speed of 250kph. And it's claimed it can do 32kms of FWD on the battery alone.

Unlike the 42.5kpl coupe, the convertible only claims a piffling 40kpl, but charge time on a domestic socket is impressive; BMW says it would be "less than two hours". It'll do 30.5kms on EV power alone, and the batteries are charged up when you coast, cruise and stop.

There are, as you'd imagine, some spurious concepty add-ons. Also included are a pair of electric scooters housed under a transparent tailgate, a camera-based proactive collision warning feature, and the interior can be pre-warmed on a cold morning so it's all toasty and warm when you go to drive it.

But still, look at it. This is definitely a vision of the future we like. Your thoughts on the arachnid-hating Wurzel of tomorrow, TopGear.communists?

See more pics of the i8 Spyder

Tags: bmw, i8, beijing