The individual shell-like rear seats feature luxurious ottoman footrests, as on an airliner, with centre armrests containing climate control buttons. Neat scrolled armrests are tucked into the rear quarter panels, to compliment those on the front doors. This rich upper cabin feel is contrasted by a striking metallic floor that uses interactive lighting to indicate changes in cabin temperature.

Interestingly, the texture extends up the lower area of each door creating a reflective mirage effect, masking the true intersection of floor and side wall. In addition, when each door is opened, a section of the floor also moves out to create a step into the cabin.

The spacious interior and low height of the FCX (1430mm) is made possible by Honda's latest V-Flow fuel cell stack. This allows a very low floor because the compact fuel cells are now packaged vertically in the centre tunnel, with the ultra-capacitors under the rear seats and twin hydrogen tanks sitting within the rear subframe. Power is doubled over earlier FCX prototypes to 100kW with a cruising range of 560 km, a significant improvement over the former figure of 355km. In addition, Honda has developed the Home Energy Station (HES), an integrated system designed not only to generate hydrogen fuel for the vehicle, but to supply electricity and heating to the home using the existing domestic natural gas supply.

Like the Asimo robot project, there's a dogged determination amongst Honda engineers and designers to develop this technology over many generations before bringing it to market. Honda also appear to recognise the inherent dilemma here: fuel cell cars need to possess a design that's different from current cars to make a clear statement, as well as being clean, affordable and attractively packaged. On the other hand they need to be visually sophisticated in classical automotive terms to entice customers to buy them. With the latest FCX concept they seem to have hit the note just right.

Dimensions: length 4720mm, width 1870mm, height