Detroit ? A Cash for Clunkers hangover hit every major automaker except Hyundai last month.

U.S. sales of cars and light trucks fell to just under 746,000 in September, down 41 percent from August.

Both GM and Chrysler were the biggest losers last month, while Ford, the healthiest of the Detroit Three, reported the smallest drop of major automakers. Of the top companies, only Hyundai posted higher sales, up 27 percent from September 2008.

Last month’s slump brings car and truck makers back to earth following a heady August. Automakers got a lift from clunkers, which spurred sales of nearly 700,000 new vehicles during the summer months.

Still, both GM and Ford said the clunkers letdown should pass by next month. They also forecast a slight recovery in sales with signs of economic improvement.