"The overall tax from BMW's two plants in Shenyang may reach 20 billion yuan ($3.3 billion) this year."

Foreign companies also now account for 30 percent of the total industrial output of Shenyang, and they employ about 20 percent of the city's population.

In the Tiexi industrial district, more than 400 foreign companies have set up shop, including General Motors, General Electric and Michelin. European Union investment in particular has changed the dynamic of the city, Zhang says.

Liu Chengmin agrees. The 34-year old local works for a Sino-French joint venture founded in 2008 to supply BMW with rear bumpers.

"The traditional factories that were left did not need any more workers," he says. "As BMW arrived here, so did many opportunities. Many suppliers came here, and it has been a great opportunity for locals like me. My company now has 100 employees, and we are taking on another 100 soon."

Zhang refuses to speculate on whether lower wages in Shenyang and the northeast were a selling point in luring the carmaker to the region.

The average wage for a skilled worker in the city is now about 3,000 yuan to 3,500 yuan a month, Liu says. The National Bureau of Statistics' most recent figures, for 2012, put the national average wage for urban workers at 3,966 yuan a month.

Zhang maintains suitable land and infrastructure are the main selling points for attracting foreign investment. Where facilities and amenities for foreign companies and their workers did not exist, the city built them.

These include a ward in the local hospital for foreigners that opened in 2010. Wu Qiong, a doctor, says the number of foreign patients seen this year will top 1,000.

"There are more and more foreigners in the city," she says.

Wu Xiaohuan, a nurse, says the influx of outsiders has coincided with Shenyang's growing economic health.

"I remember when I was 10, my mum lost her job," she says. "It was because the factory she worked in closed down. We lived on government benefits. Now there are lots of jobs for people."

In one corner of the hospital waiting room is the "BMW playpen" that has been set up for children.

Zhang says it is a reflection of the level of German investment, which has been rising in Shenyang.

On separate trips this year, President Xi Jinping and Premier Li Keqiang visited Germany, and German Chancellor Angela Merkel visited China in July.

In August, the State Council announced it would build a 120-square-kilometer Sino-German equipment manufacturing industrial park in Shenyang, geared to attract and facilitate German and wider EU investment and business.

Zhang says the details are still under wraps, but hinted the development will include a "German-style town" with accommodation, hotels and vocational schools.

"It will be the foundation of our cooperation with Germany, and the rest of Europe," Zhang says.

Chelsey Moffatt, 31, is one of the young foreigners drawn to Shenyang.

Back in the bar on Halloween night, the American turned Shenyang university teacher is dressed up as a giant apple and celebrating with her Chinese husband, Caleb Huang, 26, who is masquerading as the comic book crusader Flash Gordon.

The couple is about to open their own bar in Shenyang. They say a burgeoning trade in hospitality in the city is a weather vane for the growing level of consumer confidence, which is being driven by rising levels of employment and disposable income. With the number of foreigners in Shenyang also increasing, they believe a trendy watering hole is a sound investment.

"When I first arrived six years ago, there were barely any foreigners or foreign bars or restaurants," Moffatt says. "The city is changing every day. There are more and more jobs and industry here. It is the sort of city where the number of expats is only going to keep increasing."

The bar where Moffatt and her costumed friends are celebrating occupies a corner of an old printing plant.

Beneath the veneer of modernity is a decrepit industrial dinosaur that still bears scars of rust and ruin. It is a similar story in the rest of the city, where old factories have been refurbished and turned into art hubs or entertainment and shopping strips.

But for Zhang, Shenyang's new look represents metamorphosis, rather than just a new coat of paint.

The city, once the imperial seat of the Qing Dynasty (1644-1911), then the one-time manufacturing king of emerging China, is on the brink of a new era, Zhang says. And it is being ushered in with the help of foreign firms and workers.

"This is the rebirth," he says.

Liu Ce and Wu Yong contributed to this story.