AmeriCredit ( ACF) is a subprime auto lender that's been trying to clean up its image recently. The company has spent more than $300 million in the past year to buy two lenders that cater to higher-quality debtors. The larger and most recent of these purchases was AmeriCredit's $283 million cash purchase of privately held Long Beach Acceptance Corp., which closed Jan. 3. LBAC has a $1.7 billion portfolio of auto-loan receivables, and management believes the deal will be immediately accretive to earnings. Like Americredit, LBAC purchases auto loans from independent dealers, then securitizes them to sell the risk to third-party investors. Americredit retains the servicing rights to the loans and earns its profit as the debt is paid off. LBAC serves the near-prime (FICO scores of 630-640 out of a possible range of 300-850), compared with AmeriCredit's core customers, whose FICO scores lie in the 580-590 range. The company also bought Bay View Acceptance from Great Lakes Bancorp ( GLK), whose customers' average credit scores are in the 730-740 range, for $63 million in cash last May. According to Fair Isaac, which puts out the FICO scores, the median score in the U.S. is 720. Despite this transformation, AmeriCredit shares are down 4.3% over the past year, closing Tuesday at $25.53, which is well below the 11.5% total return (including dividends) of the benchmark S&P 500 over the same period.