Illustration by Traci Daberko

If you buy a new Ford, chances are your seatback cushion is made from soybeans and your coin tray used to be dollar bills.

When Debbie Mielewski proposed the idea of utilizing plants as car parts to Ford Motor Co. executives 10 years ago, she did not find a receptive audience. “It was a very tough sell,” says Mielewski, the technical leader of Ford Plastics Research. “We would go into every conference room at Ford, and they would say, ‘If it is that green stuff, you can get up and go. We’re not interested.’ ” Even her husband, Kevin, whom she met at Ford, told her that drivers “don’t want hay in their cars.”

“I didn’t think of it that way,” Mielewski recalls. “I thought if there were products available that were better for the environment and performed just as well, then why wouldn’t we use them instead of using limited resources?”

The corporate outlook changed at Ford when company executives became concerned about the possibility of increases in oil prices. Petroleum was being used to make 300 pounds of plastic in every vehicle and because of the unpredictable nature of the oil market, costs could have escalated dramatically. So an alternative was needed.

That was the opening Mielewski needed. Suddenly, her research group became a popular unit at the auto giant. The team of seven, which at the time was made up of all women, seized the moment, and it proved to be a great move by the company. Oil prices increased from slightly more than $50 a barrel in January 2007 to nearly $100 a barrel that December, but Mielewski’s team had already integrated soy-based seat cushions and seatbacks into the 2008 Mustang, and there was a huge savings for Ford.

As the first vehicle to use soy-based foam, the Mustang spawned a new way for Ford to do business. Today, at least 20 pounds of sustainable foam is built into each of the roughly 3 million vehicles Ford manufactures annually in North America. “Every seatback cushion has soy-based foam, and 75 percent of headrests have it,” Mielewski says. Her goal is for Ford to make plastic car parts more sustainable and to replace the fossil fuel with materials that would otherwise be found in a field or thrown away.

“Ford has been ahead of the curve on this, but it has been a slow curve,” says Chris Theodore, a Detroit-based auto consultant who has worked for Ford and Chrysler. “Clearly, everyone is concerned about our dependence on petroleum-based products, so this is an investment in a better future. In the long run, it may make a whole lot of sense.”

A visit to the sustainable-parts lab in Dearborn, Mich., reveals a setting that could be mistaken for a high school chemistry classroom if it weren’t for the unconventional materials being tested for potential use. Besides glass jars of soybeans stacked in the lab, there are mounds of cracked coconut shells, nests of shredded U.S. currency and containers of used cigarette filters that have been cleaned. What appears to be a standard black seat cushion sits in the corner. Closer inspection reveals it to be the group’s newest prototype: the Enviroseat. The parts list — soy-based foam, sugarcane-based plastic and corn-based fabric — reads more like a grocery list than anything on the assembly line. “A customer can’t tell the difference,” Mielewski says, tapping the cushion. “Durability, rebound — everything is the same.”