Carbon Motors applied for a DoE loan two years ago, but it has yet to receive funding.

Citing a long-delayed application for a Department of Energy Advanced Technology Vehicle Manufacturing loan, Carbon Motors has submitted a letter to members of President Barack Obama's cabinet asking for a decision that could make or break the company's future.

Carbon, which is aiming to build a special-purpose police car that uses a unique platform and a BMW-supplied turbodiesel engine, first applied for a $300 million Energy department loan in 2009. Carbon says that it has been planning to revive a mothballed assembly plant in Connersville, Indiana, but it hasn't been able to start converting the plant to build police cars because it is awaiting a decision on the loan.

The letter (found here), signed by Carbon CEO William Santana Li, begins with an introduction to Carbon Motors' dilemma before breaking out individual points aimed at adding relevancy to each cabinet recipient.

Timing for the letter isn't random; just last week, Carbon hosted Department of Labor representative Jay Williams, who is in charge of revitalizing communities hurt by the shrinking auto industry.

About 18 months ago, Carbon Motors detailed its E7 police car, a wedgy design that was based on studies conducted with about 3,500 police officers. Unlike other police cars, the E7 is not based on a consumer-oriented production model, a move that Carbon says frees up its ability to tailor the vehicle specifically to law enforcement needs.

The company was building momentum in early 2010 after it signed an engine deal valued at 240,000 units with BMW, but delays surrounding its Department of Energy loan application have nearly sidelined the California-based startup.