Average values of cars old at auction fell 3 per cent to £4,648 in March compared to the previous month, according to figures compiled by the National Association of Motor Auctions ((NAMA).
It said the decrease was largely due to a change in the age mix of vehicles with older trade-ins and ex-fleet vehicles being sold.
The average age of vehicles rose to 79.4 months as fleets and owners retained vehicles for longer.
NAMA committee member Mike Pilkington said: “It is expected that March will be the largest selling month of the year due to the introduction of the March registration plate.
“Although there was a 6 per cent increase in sales resulting in a total of 86,292 units, it is still well short of the 93,613 units sold in March 2011.
“However all other key performance indicators were on par with February 2012 indicating that the market remains in a relatively stable condition.
“We should see some weakness in prices but there is no reason at this stage to expect anything other than normal seasonal movements.”
Nama said year-on-year, the average price of cars at auction has decreased by just £46 from £4,694 in March 2011 to £4,648 in March 2012. Prices for Q1 were similar to those in the same period last year.