New car sales in Europe fell by 14.5% in October, the sixth monthly fall in a row, said the European carmakers' association, ACEA.
Car sales in Ireland and Spain were the worst-affected, plummeting 54.6% and 40% respectively, in October.
Even in the new EU member states, once a source of growth, overall sales fell 3.3%, despite a 12.3% rise in Poland.
With demand falling fast, manufacturers are temporarily halting production at some plants to cut their costs.
In western Europe, the number of cars sold totalled 1,034,955, 15.5% lower than the same month last year.
Austria was the only western European country which posted a growth in car sales - up 4%.
The Spanish figures were the worst since 1995, while the UK and Italy saw sales drop over 15%.
The decline was less steep in France and Germany, where registrations fell by 7.4% and, respectively, 8.2%.
ACEA's cumulative figures for the European market, over January to October, show a fall of 5.4%, which had been blamed on the financial and economic crisis.
Figures show that the worst-hit manufacturer, with sales down 49.4%, was Chrysler.
General Motors saw sales drop 25.2%, while Volkswagen sale figures had the smallest fall, down 7.6%.