Sales of used cars fell again in August, according to Manheim’s Dealer Dashboard.

While August is traditionally quiet, a fall in average used car sales per dealer from 12 in July to an average of 11.5 means that, excluding the half-month that is December, overall sales levels have dropped to their lowest level in more than 18 months.

“It almost goes without saying that it is extremely tough out there on the forecourt,” said John Simpson, managing director of Manheim Retail Services.

But the main event occurs in September with many retailers aggressively pushing the new 61 plate change and gearing up for a major new and used car sales push.

“Sales of a new car normally create a used car retail opportunity, so the overall market dynamic is stimulated by new car sales,” Simpson said.

In the wholesale market, Mike Pilkington, managing director of Manheim Remarketing said average wholesale stock for retail values increased 1% in August by £62 to £7,702. Values are on a par with August 2010.

In the stock for retail segment average first time conversion rates at 62% gained 3% and are now 8% higher than June’s low of 54%, the one exception is the large family segment, which has seen a drop of 5%.

Average part-exchange values may have dipped by 3% to £2,292 in August, but look at the figures closely and values have held up very well despite the ageing profile of stock.

The fall is largely a result of an 8% fall in the large family segment, driven by a considerable increase in age.

“All indications suggest we will see the influx of part-exchanges and fleet returns as expected later in the month and, while the cleanest examples will convert into healthy values, poor examples will need to be brought up to an acceptable standard before buyers will take them on,” Pilkington said.