Dealers bought almost 9 million vehicles at National Auto Auction Association member auctions in 2009, down 6 percent from 2008, according to the group's 13th annual survey.
Vehicles sold at the auctions' physical and online sites were valued at almost $81 billion last year, down just 3 percent, the survey found. The difference between units and prices reflected a steady rise in used-vehicle prices during the year.
The association's report on the state of the auction industry is based on responses from 217 of the association's 312 members.
Citing the economic downturn and other issues facing the auto industry, NAAA President Dave Angelicchio said the declines were expected. This is only the third year-to-year decline in 13 years, he said.
"The survey results show the strength and depth of a mature industry that, despite various challenges over its seven decades, has demonstrated its resiliency," Angelicchio said in a statement.
Other survey findings:
-- The auto industry sent 15 million vehicles to auctions in 2009, down 15 percent from 2008.
-- The average price per unit increased 3 percent in 2009 to $9,026.
-- Fleet, off-lease and repossessed vehicles collectively represented the largest share of units sold at auction last year, at 47 percent. Vehicles consigned by dealers represented 39 percent of the vehicles sold. Factory-owned units represented 10 percent, and the rest came from other sources.
-- All but 1 percent of auctions have detail shops; 92 percent have repair and paint shops; and 98 percent provide mechanical services.
The survey was conducted by LarsonAllen, of Arlington, Va.