Car production lines keep on rolling but buyers remain scarce and sales in Europe tumbled again in the first three months of this year.The lack of purchasers is putting further pressure on manufacturers as they burn through cash. The European car makers association, which counts all the region’s manufacturers as members, said sales were down by 17.2 percent in the first quarter compared with the same period last year. In March they fell for the 11th straight month, but the decline was less steep that it has been with new car registrations nine percent lower than a year ago. However, government cash bonus schemes for motorists who scrap older vehicles meant sales in Germany, the region’s biggest market, jumped almost 40 percent in March and were up eight percent in France and 0.2 percent in Italy. March sales were worst in Ireland where they were down by two thirds and in Britain they were over thirty percent lower.