September Auto Sales Go Clunk Edmunds.com reports that âSeptemberâs light-vehicle sales rate will fall to 8.8 million units . . . the lowest rate in nearly 28 years, tying the worst demand on record. After the cash-for-clunkers program boosted August sales to their first year-over-year increase since October 2007, demand has plunged. In at least the last 33 years, the U.S. seasonally adjusted annual rate has only dropped as low as 8.8 million units once â in December 1981 â with records stretching back to January 1976.â The S&P cash for clunker rally seemed to start around 975 on the S&p on all the cash for clunker talk and huge July Aug auto sales. I'm wondering if most of those 90 points on the S&P will be erased if now we back to crap.