Wholesale used vehicle prices softened again in September, the fifth consecutive month decrease, according to the latest Kontos Kommentary from ADESA Chief Economist Tom Kontos.

September’s modest year-over-year increase in average prices reflects a higher percentage of institutional sales of late-model vehicles this year versus last, and therefore masks the softness in prices seen by looking at those sales on a disaggregated basis, says Kontos. Improved retail sales of used vehicles cushioned the blow to wholesale prices from growing supply.

According to ADESA Analytical Services’ monthly analysis of Wholesale Used Vehicle Prices by Vehicle Model Class, wholesale used vehicle prices in September averaged $9,557 — down 0.4% compared to August but up 0.8% relative to September 2013.

Average prices for minivans were up significantly, but this reflects an increase in the percentage of current and one-year-old models sold in factory sales in September, according to ADESA. Trucks and cars moved in opposite directions — with prices for trucks rising significantly on a month-over-month and year-over-year basis, while cars showed major sequential and annual price declines. Crossovers also showed price declines.

Prices for used vehicles remarketed by manufacturers were down 4.2% month-over-month and down 3.3% year-over-year, as manufacturers sold off elevated program vehicle inventories, according to ADESA. Prices for fleet/lease consignors were down 2.0% sequentially and down 1.1% annually, while prices for off-rental “risk” units within this segment were down again significantly.

For dealer consignors, there was a 1.9% average price decrease versus August, although prices were up a modest 0.3% relative to September 2013.

Based on data from CNW Marketing/Research Retail, used vehicle sales in September were up 4.1% month-over-month and up 4.6% year-over-year.

And based on figures from Autodata, sales of certified pre-owned (CPO) vehicles were down 15.4% versus August, but that was based on three fewer selling days. A better reflection of certified used vehicle demand is that September CPO sales were up 19.7% from the prior year.

This Kontos Kommentary analysis is based on nearly six million annual sales transactions from more than 150 of the largest U.S. wholesale auto auctions, including those of ADESA as well as other auction companies. ADESA Analytical Services segregates these transactions to study trends by vehicle model class