According to an analysis of Cox Automotive’s vAuto Live Market View data estimates, retail used-vehicle sales in September1 decreased month over month compared to August.
A total of 1.42 million used vehicles were sold at retail – from both franchised and independent dealers – during September, down 5.2% month over month and up 6.6% year over year. Days’ supply of used vehicles in the most recent report was 48, up four days from the beginning of September and up one day compared to the same time last year.
The estimated monthly retail used-vehicle sales number is based on vAuto Live Market View data from the most recent 30-day period. This change aligns the sales data in the monthly estimated sales report with the monthly inventory report. The historical data in the downloadable file has been updated to reflect comparable 30-day sales data.
Monthly Used-Vehicle Retail Sales Volume

Scott Vanner, manager of Economic and Industry Insights at Cox Automotive, noted: “Used-vehicle retail sales fell more sharply than new-vehicle sales in September. Seasonal patterns and affordability pressures were likely the main drivers of this pullback. The recent reduction in the Federal Reserve’s rate has not yet resulted in lower used auto loan rates. Rather, a modest rise in subprime rates and an increased proportion of subprime loans have elevated average used auto loan rates to over 14%.”
The retail used-vehicle sales estimates are based on observed unit changes tracked by vAuto, a Cox Automotive brand specializing in inventory management. The vAuto Live Market View database provides guidance on sales pace and volume over time. Full-year sales volume, based on registrations and other sources, is updated annually.
CPO Sales Down Sharply in September
Certified pre-owned (CPO) sales decreased 19.4% month over month in September, according to data reviewed by Cox Automotive. CPO sales in September were up 6.7% year over year, which is in line with the broader new-vehicle market. September’s CPO sales are estimated at 194,020, down from 240,620 in August. Year to date, CPO sales are running 2.7% higher than the same period last year.
1The estimated monthly retail used-vehicle sales number is based on vAuto Live Market View data from the most recent 30-day period. This change aligns the sales data in the monthly estimated sales report with the monthly inventory report. The historical data in the downloadable file has been updated to reflect comparable 30-day sales data. The 2024 implied sold and days’ supply numbers affected by the CDK outage have been normalized.