August registrations crashed from more than 500,000 last year to 74,444, a drop of 85.3%, as the market continued to re-adjust following the dropping of the annual plate change.

Carmakers and dealers had expected the fall, though many over-ordered through August and stock levels going into September were high. Private buyers stayed away and there was a marked shift towards fleet business.

Christopher Macgowan, Society of Motor Manufacturers and Traders' chief executive, said when the figures were released in the first week of September: “A significant decline was expected this August and consumers were clearly waiting for the V-plate in September. We could be on course for a September market of 400,000 units.”

September is thought to have started relatively slowly with sales managers expecting an acceleration through the second half of the month.

That was the pattern with the T-plate change in March but it seems unlikely to be repeated this month.

The August figures were lower than February's 84,000 but some analysts took comfort from the fact that they were still almost double last year's July total of 37,896.

Although 1999 is bound to be a transition year, there are already signs of the market peaks being smoothed out by the twice-yearly plate change.

Total registrations to date are 1,433,097, a drop on last year of 14.7%. But a 400,000 September market would bring the total back on par with last year and the SMMT is expecting the final market to reach 2.22m, about 1% down on last year. Sales in the final quarter are expected to tail off as customers wait for the Millennium before buying.

The top selling car in August was the Citroen Saxo which jumped from 10th place in July, suggesting a strong element of seasonal, daily rental replacement. Fiat Punto also did well through July and August. Both cars are on run-out with new models due in the next few weeks.