Now, just as in the housing sector, the auto industry is suffering, too.

Borrowers are falling behind on their car payments at a rate faster than in other recent downturns. And losses are considerably worse. Auto lenders sustained losses on about 3.4 percent of their loans in the first quarter, a rate about 30 percent higher than in 2002, according to data from Moody’s Economy.com. Even some of the most creditworthy borrowers are stressed.

Recently there have been a few small signs of improvement. But auto lenders have struggled to find investors willing to buy packages of new loans. Just as in the mortgage markets, a sterling credit rating  the bond insurer’s seal of approval  is no longer trusted.

“It’s a challenge, but it’s not a crisis,” said William F. Muir, president of GMAC, the financing arm of General Motors that is now operated as a joint venture.

As the pool of money available to auto lenders has dried up, they have cut back on making new loans. Since late last year, nearly every auto finance company has tightened its lending standards. They are forcing borrowers to put more money down. They are also demanding higher monthly payments and requiring stronger credit records and more stringent documentation.

Subprime auto lenders have been forced to pull back the most. AmeriCredit, a big subprime finance company, said it would issue about $3 billion in new auto loans this year, compared with $9.2 billion in 2007. That translates into around 340,000 fewer vehicles being financed this year. But lenders catering to less risky borrowers are also retrenching.

“Capital One is pulling back, Citi is pulling back, HSBC and Wells Fargo are pulling back,” said Mr. Ryan, the analyst. So are the finance entities that serve the major automakers, like GMAC, Chrysler Financial and Ford Motor Credit. “What you are seeing at AmeriCredit is probably happening everywhere else, but probably to a lesser degree.”

Many dealers say that buyers who would have been shoo-ins for a loan a year ago are now being turned away. Ken Somerville, business manager at Pedigo Chevrolet in Indianapolis, said the tougher standards were having a “significant impact” on his ability to help customers get financing and close a sale.