The growing popularity of new compact crossover utility vehicles is putting pressure on the prices of used CUVs.
"These vehicles have been red hot," said Ricky Beggs, editorial director of the Black Book. "We've seen wholesale prices really fall in the last month."
The Black Book tracks the depreciation and wholesale prices of used vehicles. In August, the price dealers paid for used compact CUVs fell 2.4 percent to an average of $13,370. Over the past year, they are down 13.9 percent.
(Read more: GM unveils updates to its hot SUVs)
What's behind the drop?
"There have been more and more trade-ins of 3- and 4-year-old compact crossovers because buyers want to upgrade to the newer models," said Beggs.