The trade body said the 3.2 per cent dip compared to last year owed much to concerns over consumers' ability and willingness to purchase big ticket items when faced with high debt levels, rising interest rates and political instability. The SMMT said it expected to see registrations of new cars for the March plate change month total around 425,000 units, worth some £6bn. That would be a 10,000 unit decline over 2006 volumes which reached 435,847 units.