CHARLOTTE, N.C. — Two months ago, salesmen at a General Motors dealership in Huntersville, N.C., had to ask car buyers with good credit scores — 700 or better — to prove their income and residency. Now those more rigorous standards are being applied to only about 25 percent of prospective buyers — the traditional percentage of marginal customers.

Auto loans could become even more widely available in the coming days, with news that lender GMAC Financial Services is receiving $5 billion in federal bailout money. GMAC, GM’s financing arm, says it will resume auto financing “for a broader spectrum of U.S. customers.”

While the economy isn’t improving, GMAC’s announcement is the latest sign that the credit freeze is thawing, especially for those who want to buy from American automakers GM, Ford and Chrysler. In recent weeks, banks have become more willing to make loans, dealers say.

With GMAC poised to offer loans again to people with credit scores in the 600s, some dealers expect to be able to bring back low-interest financing promotions. GMAC finances about 75 percent of cars sold at GM dealers.