Westlake Village, Calif. A new study by J.D. Power & Associates' Power Information Network (PIN) shows 3-year-old vehicles either turned the fastest or were among the fastest-turning vehicles in the first quarters of 2006, 2007 and 2008. PIN reported that the odometer reading on these 3-year old vehicles has been declining, down more than 1,000 miles from 2006 to 2008. The average selling price also declined, about 0.5% to $17,738. In contrast, the average transaction price (less rebate) of a new vehicle has climbed 3% to $27,771 during the same time period, according to PIN.