Tokyo, Japan | Toyota's three-seater exoskeleton car and an electric vehicle with touch screens that turn it into a "digital space" are among the concept models that will be on display at the Tokyo Motor Show.

The biennial event will also focus on self-driving cars and the latest environmental technology as firms look to tap growing demand for green vehicles, seen as the next evolution in the global automotive industry.

"This year, autonomous driving will be a big trend, with the Japanese automakers really showing what they are trying to do and trying to show that they can match, if not do better, than what Silicon Valley is up to," said Hans Greimel, Asia editor for the Automotive News.

The show's 44th edition will feature 160 exhibitors including global auto giants and parts suppliers from a dozen countries.

It starts a week after Honda said it would put a commercialised self-driving car on the road by 2020, challenging rivals Toyota and Nissan, which are also betting on the future of vehicles that can drive and, in some case, park themselves.

Google has been testing self-driving cars in Silicon Valley, as have US-based Tesla and General Motors, while Nissan has vowed to put an experimental automated car on Japan's highways as soon as 2016.

At the show, Nissan, a leader in electric vehicles (EV), will show off an EV concept car without knobs and buttons, replaced by tablet-style touch screens featuring controls and maps on a white instrument panel.

Music, videogames and movies can also be played on the screens.

"The car becomes a digital space when it's parked," said Nissan product planning general manager Hidemi Sasaki.

"You can use it as a gaming room, movie theatre...or you can chat online with your friends."

Toyota's Kikai vehicle conjures images of the Terminator films with some of a usually hidden underbelly -- including fuel tank and hoses -- exposed, giving an inside look at the car's machinery. 

The automaker said its concept car shows off "the fundamental appeal of machines: their fine craftsmanship, their beauty, simplicity, and their fascinating motion".

- Fuel-cell future - 

Toyota and Honda will also exhibit their latest fuel-cell offerings, after Toyota last year started selling the world's first mass market fuel-cell car in Japan.

Toyota is hoping to sell tens of thousands of the four-door Mirai -- which is powered by hydrogen and emits nothing but water vapour from its tailpipe -- over the next decade, as it looks to stop producing fossil-fuel based cars altogether by 2050.

Honda's rival fuel-cell features a cruising range of more than 700 kilometres (430 miles), and generates electricity that could help supply power to a local community in an emergency situation, it said.

Toyota's FCV Plus similarly functions as a power source for homes and communities as the auto giant aims to turn fuel cell vehicles from "eco-cars into energy-cars", it said.

The firm's hybrid gasoline-electric offerings, including the Prius, have sold more than eight million units since their launch in 1997. 

But a limited driving range and lack of refuelling stations have hampered development of fuel-cell and all-electric cars, which environmentalists say could play a vital role in cutting greenhouse gas emissions and slowing global warming.

Again this year, most US-based automakers, which have not attended the Tokyo Motor Show since before the global financial crisis, are staying away, a reflection of their puny presence in the Japanese market.

Foreign carmakers have long complained that they were effectively shut out of Japan through tariffs and other barriers, although luxury brands tend to enjoy success in the world's number three auto market after China and the United States.

Among the overseas automakers attending are BMW, Peugeot Citroen, Porsche, Jaguar and crisis-hit Volkswagen, which is embroiled in one of the biggest scandals in the history of the automobile sector.

The German auto giant has admitted it had fitted 11 million of its vehicles with software designed to cheat official checks.