An update from Autodata Corp. — In October, 838,052 cars and light trucks were sold in the U.S., for a seasonally adjusted annual rate of 10.46 million units. The federal “Cash for Clunkers” program stimulated sales in July and August, cannibalizing September’s demand, which sank to 9.22 million, about half the 17 million unit sales that the industry had enjoyed for the past decade. General Motors is now making business decisions with the assumption that 10 million units will be the new “normal” annual rate for a while.

UPDATE: November numbers are now available. The SAAR for November 2009 was 10.93 million vehicles.