Volkswagen’s plans to build a two-seater turbodiesel convertible roadster, the Blue Sport, have been on-again, off-again since the concept first appeared at  the 2009 Detroit auto show. Now it looks as if those plans could fade entirely. The German automaker says it just doesn’t see the kind of projected sales numbers it needs to justify the build.

VW wants to triple sales

Although the U.S. is the world’s largest market for sports cars, it is the American arm of VW that sees the new model as a distant priority. In light of the company’s announced plans to triple U.S. sales to 800,000 units annually by 2018, Volkswagen of America feels it should keep its eggs in existing baskets.

Jonathan Browning, Volkswagen of America’s CEO, said:

“To get to 800,000 units, we don’t need to keep adding to our portfolio of models. We’re concentrating on our core models.”

Sales of 50,000 needed to justify Blue Sport

The company says it needs to anticipate a minimum of 50,000 sales globally in the model’s first year to justify its construction. All projections at this point fall far short of that number.

Uli Hackenberg, VW’s head of Research and Development, said that the engineering is completed for the car, but the numbers aren’t there to move ahead. He told the British car site “What Car?”:

“At the moment, there’s no official release for the project. We are fighting for it as it fits with the VW brand, but we need demand and volume and we need dealers to get behind it.”

Porche and Audi sister models may be shelved, too

Volkswagen has long held a close relationship with Porsche. Sister models of the Blue Sport were also in the works for Porsche and its sister company, Audi. If the Blue Sport is shelved, it is likely the Porsche and Audi models will follow. The idea has also met resistance from Porsche. While the Porche has considered using the Blue Sport as a successor to the 550 Spyder, it also is concerned that the model would cut into sales of its higher-end Boxster sports car.