But it is not stopping them from trying.

At the Tokyo Motor Show this year, many car makers will twin futuristic technologies, such as advanced fuel cells and drive-by-wire, with head-turning designs and quirky concepts to upstage rivals at one of the world's five biggest auto shows, opening from 22 October to 6 November.

Among the three concept cars from Toyota Motor Corp, Japan's top car maker and a leader in clean-vehicle technology, is the gull-winged Fine-X, a new fuel-cell car that has four independently steered wheels which enable it to rotate on the spot.

With no noted output or driving range improvement over its existing fuel-cell vehicle, Toyota is playing up the car for other eco-friendly features such as a body and interior that use biodegradable fibres and plastics.

The maker of the popular Prius hybrid car will also show off a one-seater "mobility machine" called the i-swing, which runs on three wheels at high speeds and upright on two wheels in slow mode.

The vehicle is an evolved version of the PM, which stole the limelight at the Tokyo Motor Show two years ago.

Nissan limelight

This time that privilege will probably go to archrival Nissan Motor Co's Pivo concept. The egg-shaped cabin-on-wheels uses drive-by-wire technology to allow the cabin to spin around and "back out" of a parking space facing forward.

Nissan's Pivo allows steering
through electronic signals

Drive-by-wire eliminates the mechanical linkages between cabin and chassis to enable steering, braking and shifting through electronic signals.

The system is not new to the industry, however, having been put prominently on the map by General Motors's (GM) sleek Hy-wire concept car at the Paris Motor Show in 2002.

"With the Pivo concept, we want to demonstrate the myriad possibilities that drive-by-wire could achieve," Pivo's chief designer, Masato Inoue, said at a preview of the car last month.

Fuel-cell cars

Over at Honda Motor's stand, Japan's third-biggest car maker will show off the FCX concept, which proposes the future styling of a fuel-cell car once the industry manages to develop smaller fuel-cell stacks and store more hydrogen in smaller tanks.

With the compact mock fuel-cell stack tucked between the driver and passenger seats, and two small hydrogen tanks between the rear wheels, the FCX has an ultra-low floor and more cabin space than fuel-cell cars now being tested on the road.

"This is what we would like fuel-cell cars to look like," Honda Executive Chief Engineer Yozo Kami said.

Among non-Japanese brands, DaimlerChrysler AG will show the F600 Hygenius fuel-cell car for the first time in Japan. The compact model has a driving range of over 400km - 100km short of being considered practical.

"This represents a major step towards bringing the fuel-cell drive up to full production maturity," DaimlerChrysler Research and Technology Chief Thomas Weber said in a statement. The German-US company is aiming to mass-produce zero-emission fuel-cell vehicles some time between 2012 and 2015.

However, most car manufacturers consider that timeline ambitious.

Roadblocks

One fuel-cell car is said to cost at least $1 million to build, not to mention the work needed on infrastructure and legislation to set up hydrogen fuelling stations on public roads.

With those roadblocks in mind, Mazda has an interim solution: the Premacy Hydrogen RE Hybrid, a close-to-ready minivan concept that can run on petrol, hydrogen or an electric motor. Mazda says it aims to market the dual-fuel vehicle in the near future.

General Motors will be absent
from this year's motor show

Also making its world debut at the Mazda stand is the hydrogen RX-8 rotary engine sports car, which the Japanese car maker plans to begin leasing soon, and the production model Tribute hybrid SUV due for launch shortly.

All told, 38 makers will have 45 world premiere passenger cars on display at the show, including 11 from foreign brands such as Ford, Chrysler, Volkswagen and Hyundai.

Conspicuously absent from that list of world debuts is Detroit-based General Motors, whose top brass will also be staying home to deal with growing troubles after former parts-making unit Delphi Corp filed for bankruptcy last weekend.