Business Green: The government was yesterday facing fresh calls for the introduction of a “scrappage scheme” to encourage motorists to trade in older polluting cars for newer models, after figures revealed sales of new cars last month dropped by nearly a third on last year. Sales of new cars during March, traditionally a strong month for the industry, fell 30.5 per cent to 313,912 cars, according to figures from the Society of Motor Manufacturers and Traders (SMMT), prompting fresh calls for a …