Global car sales is forecast to fall 8.2 per cent this year by research firm JD Power, while China's sales figures were up 10 per cent in March.

The biannual Shanghai Auto Show comes on the heels of Sunday's Formula One Grand Prix event in the city.

The Porsche car company, which unveiled its Panamera luxury car to launch the show, said its decision to reveal the vehicle in China signalled the rising importance of the country's motor market.