Cars Cheaper in 2010

According to the Used Car Prices Index, a motor industry publication by CAP, used car prices in August 2010 are cheaper than a year ago.
Average prices are stated to be 3% lower than 12 months ago, but prices vary according to sector.
The best performing sector was the 4X4’s which showed an 11% increase while city cars and superminis were down by 10%.
Is it the case that with car prices being lower this year,  is it a factor in motor dealers showing an increase in their net profits of 18.5% in the first 6 months of 2010?