VW CEO: Mexico key in quest to become world's top carmaker

Mexico City, Mexico (CNN) -- At the lavish opening of Volkswagen's latest plant in Mexico, the company's boss and Mexico's new president join hands to push a button. A vast sheet drops to reveal a gleaming assembly line for engines -- surrounded by newly hired VW employees waving Mexican flags.

It's an obviously symbolic moment: Mexico relies heavily on multinational car firms to power an important sector of its economy. The country is currently the fourth largest auto exporter in the world.

"Mexico is our main product delivery hub for the USA," VW CEO Martin Winterkorn tells CNN. "In this regard Mexico plays a very important role -- specifically for the US market for which we want to produce and sell one million vehicles by 2018."

The United States has become a vital market for VW: Sales jumped 26% in 2012 and they expect further growth this year, which helps to offset a decline in Europe. This week, Germany -- the economic engine on which the eurozone has come to depend -- reported its economy shrank in the last quarter.

CNNMoney: European car demand near 20-year low

"We do not expect Germany to sustain a heavy drop in GDP. We expect slight growth and stabilization in the automobile market," says Winterkorn. "What concerns us is Southern Europe. We don't see any growth there, but we are hopeful that there will be light at the end of the tunnel perhaps in 2014/15."

The former physicist has a reputation for meticulous attention to detail and is focusing on making VW the biggest carmaker in the world by 2018. The company just announced record global sales. Whether his greatest ambition can be achieved may partly depend on the biggest prize of all: China

"We expect an overall market growth of 8% in China," he says "We have invested and will bring new plants online in China. We think that we'll grow."