In 2008, 1.6 million vehicles were repossessed, an increase of 12 percent from the previous year.
From here citing this source.
How much does it cost a bank to have someone repossess a car? "[A]uto dealers and banks will pay rates between $250 and $400 per vehicle."
The number of new cars sold in the U.S. in 2008 was something on the order of 11-12 million.