Land Rover now says it will definitely make an all-new Defender in 2015. And here are two concepts, called DC100, to prove its serious. While sister brand Range Rover has very much gone to the ball this year with the new 2011 Land Rover Defender was looking like the forgotten Cinderella of the British 4x4 family.Land Rover bosses admit they aren't quite sure what the new Defender has to be, under the skin.But Land Rover design boss Gerry McGovern told us a vehicle with approximately this look can fit over pretty much any mechanical base.The idea of showing these different DC100 versions is to prove a next-gen Defender must be configurable.The 2011 Land Rover Defende has a 2.0-litre diesel engine. The Sport has a turbo petrol. That makes it the first petrol Defender for years. Immense ground clearance, boxy sides and short overhangs make these concepts as good as any road car can be, when the road runs out. To make them even better, there's a new automatic terrain response system that automatically sets all the driver assist systems. It senses the wheel travel, wheelslip, and the texture of the ground ahead.