NEW YORK — Dismal September auto sales may be one of the clearest signs yet that faltering consumer confidence and tighter credit are squeezing consumer spending.

"It went from the housing market to the car market," said Reggie Chambers III, sales manager at Anderson Automotive Group in Baltimore.

Ford Motor Co., Toyota Motor Corp., Chrysler LLC and Nissan Motor Co. all reported U.S. sales drops of more than 30 percent yesterday; General Motors Corp. said sales were down 16 percent. The final two weeks of the month were especially grim for car dealers as stocks tumbled, Washington dickered and credit markets froze.

To be sure, the auto industry has been reeling all year, thanks to falling home prices and record gas prices, which soured buyers on the light trucks and large cars Detroit had depended on for profitability. Now, the credit crisis is making things worse, as buyers struggle to qualify for loans and automakers scale back leasing.

The stock market roller coaster made buyers even more nervous. Stocks had a one-day loss, on paper, of $1 trillion Monday, for the first time in history. As the market fell, some luxury vehicle buyers called Toyota dealers asking for refunds on deposits they'd made, said Don Esmond, senior vice president of auto operations for Toyota in the U.S.

The past two weeks were "tantamount, really, to a natural disaster," said George Pipas, Ford's top sales analyst. Showroom traffic looked like it does around a large storm, or in the weeks following the Sept. 11, 2001, terrorist attacks, he said.

"There's just scare in the air," said Kitty Van Bortel, who owns both a Ford dealership and a Subaru dealership in Rochester, N.Y. "My opinion would be that sales are down because of the unknown, and that's always the worst. People really don't want to make a large purchase not knowing what exactly is going to happen."