A magnesium shortage could have big problems downstream for the vehicle industry

China's energy crisis has led to the shutting of magnesium smelters which produce the element used in the bonnets, bodies and doors of cars.

This means a longer wait for the importation of certain popular models.

Motor Industry Association Chief Executive David Crawford says it was bound to happen.

He says China shut down 25 smelters and reduced others to 50 percent capacity and it was a matter of time before the world was caught out.