Shares of AmeriCredit Corp., which lends to car buyers with poor credit histories, fell more than 6 percent Thursday on concern about rising defaults and rating downgrades of bond insurers. Investors are worried that Ft. Worth-based AmeriCredit might have to pay higher costs for bond insurance as providers such as MBIA Inc. face potential credit-rating cuts, said Scott Valentin, an analyst for Friedman Billings Ramsey & Co. Credit losses are spreading in the banking system from mortgages into consumer and automobile loans.

Sovereign Bancorp has stopped making auto loans in the Southeast and Southwest. Capital One Financial Corp. has said the slower economy made it harder for borrowers to keep up with car payments. Shares of AmeriCredit slid 68 cents, or 6.1 percent, to $10.52, on the New York Stock Exchange.

The third M3 derivative from BMW has been unveiled and is set to hit showrooms in April, in news that could be very exciting for potential car loans customers. It might be time to sell that used BMW and splash out on the new convertible, which has a retractable hard top and a seven-speed double clutch transmission.

As an alternative to the standard six-speed option, this type of gearbox is said to offer the “highest levels” of driving performance and really give drivers a great ride. The M3 Convertible delivers 105hp per litre in its brand-new engine, with stats clocking in at zero to 62mph in 5.3 seconds. It is expected to come with a price tag of £54,655 upon its April release, giving new car buyers something to seriously consider in the preceding months.