Cash for Clunkers didn't start till July 1, 2009. How did a program that didn't exist raise car prices for six months before?
Supply. People are holding onto their cars longer. The cash for clunkers program hit the used car market when it was already down. Further, financing is harder to get, so supply is down and demand is restricted only to those who can self-finance. It all works out according to supply and demand . . . but the bottom line is a huge number of the cars that are sold each year, 690,000 per your numbers, were destroyed by the government. Prices have risen by 10%. It was a stupid and destructive program that has hurt the poor, the middle class, and the thrifty.