About every half hour, the outer shell of a Volkswagen Passat is transformed from a dull battleship gray to a sparkling white, black, tungsten or reflex silver.

Computer-controlled robots in the paint shop of the new Chattanooga auto assembly plant spray on one of the four colors, which will double in number to eight finishes later this year.

The plant's paint shop is methodically stepping up the number of new vehicles it's producing with a focus on quality and the environment, officials said last week.

"Quality is always the first goal," said Lothar Grensemann, the paint shop's general manager.

The all-new Passat is slated to go on sale in September. High quality will be needed for the new Passat, which is seen as a keystone to VW's plan to nearly triple annual sales in the United States to 1 million by 2018.

J.D. Power and Associates recently ranked Volkswagen 29th out of 33 brands related to how many problems buyers had in the first 90 days of ownership. Lexus topped the list David Tulis 6/30/11?? with the fewest problems, and Dodge finished last with the most.

Auto analyst Jeannine Fallon of said past buyers' disappointment with quality is a problem the carmaker has to solve.

"No marketing can solve that problem independently of actually attacking it from an engineering perspective," she said. "Then it takes a layer of marketing to move the needle. That's something the brand needs to overcome."

Executives respond

That fact isn't lost on VW executives.

Frank Fischer, chief executive of VW's Chattanooga operations, said the auto plant is designed to incorporate the best practices from the carmaker's more than 60 factories worldwide to make better vehicles.

The plant adopted a slogan - "passion for detail," Fischer said. Early on, he and other top brass instituted daily test drives of Passats around the factory to give workers feedback about quality.

Michael Macht, a Volkswagen board member in charge of production, said during the plant's grand opening in June that "quality is the most important thing that we are targeting" for the automaker's revival in the U.S. market.

"If we do not achieve a good quality in this product, then we are really in deep trouble," Macht said. "This is how we installed the processes here and everything we are doing with our management team and our staff is to ensure that we have a strong focus on quality."

"Best in class"

Grensemann said that in the paint shop, training is "the main thing" as the German automaker aims to achieve "best in class quality for our cars."

Paint shop employees have been working one shift, but this week it's slated to start moving toward a second, Grensemann said.

"You can only ramp up when you produce day by day quality and more stable quality," he said.

In the near future, Grensemann said, the plant will paint 233 vehicles a shift, or 31 units an hour. Currently the shop is painting about 120 vehicles per day, he said. David Tulis 6/30/11 Rather, say what the rate per shift or per hour is, for comparison.

Unique plant

Fischer said the best practices design elements of VW factories were combined with some new ideas in such a way "that I can say this plant is unique."

The paint shop, for example, has an innovative body transport system in the pretreatment area to better fight corrosion and rust and help seal the vehicle, officials said.

The system is able to turn over a body in large bathes, permitting cleaners, solvents and sealers to reach every corner and use less material at the same time, Grensemann said.

Also, he said the paint shop is the first in the world to put into effect a dry scrubber system that produces no liquid paint sludge in the plant. In the new method, air is used and reused and filtered through limestone, which is then sent to the cement industry and turned into concrete, Fischer said.

Estimated water savings are 50,000 gallons per day, according to Fischer. Over the course of a year, savings will equal 12.5 million gallons, he said.

Jonathan Browning, CEO of Volkswagen Group of America, said last month in Chattanooga that quality has been "a tremendous focus right from the beginning."

Surveys satisfying

Browning points to the Consumer Reports consumer satisfaction surveys which showed the highest rating for the VW Golf TDI among U.S. customers.

"Over 90 percent said they would buy that vehicle again," Browning said. "So I think you can look at different sources of information and interpret them in somewhat different ways. At the same time, we take the J.D. Power reports very seriously and are addressing some of the issues in terms of what I would call the execution of some of the functionality of the vehicle for the U.S. market."

Temperature controls for heating and air conditioning have been altered to better suit the American market and the Bluetooth technology has been added to offer better wireless services, Browning said.

"It's the first time you are seeing a German-engineered vehicle in this midsized sedan segment that is really affordable," Browning said. "We're seeing sales momentum today that is founded upon strong products, strength in brand and quality performance."

Staff writer Dave Flessner contributed to this story.