For Americans wanting to buy a car, almost every single option except paying cash has gotten harder in recent months.

Leasing options have dried up as automakers have shrunk their finance operations or shut them down completely — it’s increasingly hard for people with superior credit to get a loan, much less for auto dealers to buy cars on credit to put out on the lot.

The economic crisis has hurt the bottom line of hundreds of auto dealers already facing tough times because of high gasoline prices and an inventory full of unpopular trucks and SUVs.

Earlier this week, Bill Heard Chevrolet, one of the biggest auto dealer chains in the country, announced it was shuttering its 13 branches.

“Things are dead,” said Cody Lusk, president of the American International Automobile Dealers, which represents 11,000 auto dealerships selling only international brands — like Toyota, Lexus, Jaguar and Volvo.

“People aren’t even coming into the showrooms,” he said. “They are afraid. There is a lot of credit tightening.”

As Congress aims to finish its financial bailout package by the end of the week, the American Financial Services Association, the national trade group for the consumer credit industry, is lobbying for a small but, it argues, critical change in the bailout bill that would allow the Treasury Department to buy securitized auto loans.

The association is working to broaden the bill’s definition of financial institutions to include finance companies. This would mean companies, such as GMAC Financial Services, Ford Motor Credit Co. and other smaller lending institutions that extend lines of credit to auto dealers, could have the Treasury buy back some of the debt.

“The importance of adding them to the definition is spelling out clearly to Wall Street that auto finance paper is on a level playing field,” said William Himpler, AFSA’s executive vice president for federal affairs.

Himpler, who has been pushing for the addition since the first drafts of the Bush administration’s plan were released, says the White House signaled in a conference call Thursday that part of its plan is for the Treasury to buy automobile debt.

AFSA, along with several other associations, including the Securities Industry and Financial Markets Association, sent a letter Thursday to Capitol Hill expressing the need for urgent action to pass the bill.

“The financial industry is advocating that Treasury have maximum flexibility to buy assets,” SIFMA spokesman Travis Larson wrote in an e-mail. “Clearly a large range of financial products fall under that umbrella, including securitized auto loans. We don’t want to see Congress make only x, y and z products eligible for the program, only to find out after Congress has left for recess that the economy is being dragged down by products a, b and c, but Treasury’s hands are tied because the list was too narrow.”

So far, the National Automobile Dealers Association, which represents domestic and international brands, and the American International Automobile Dealers Association have been pushing at the more macro level for the bailout package to pass Congress.

“We still hold that auto loans and auto financing is not part of the bigger problem,” NADA’s Bailey Wood said. NADA supports the package as way to infuse more liquidity into the market, Wood said. He declined to comment on broadening the definition of financial institutions.

Still, it hasn’t been all bad news for the auto industry. Earlier this week, automakers won a huge victory, securing $25 billion to help build more fuel-efficient vehicles in the House spending bill, which is expected to pass the Senate.

“Everybody is driving towards getting advanced technology cars on the road,” one automaker lobbyist said. “Having access to capital is critical to doing that.”