Car sales appear to be stuck in reverse with a car buying index revealing a "significant" decline in the number of people planning to buy a car in the next six months. Sainsbury's index, which tracks the number of people planning to purchase a vehicle on a six-monthly basis, predicts spending on cars over the next six months is set to decrease. The research shows that 6.86 million people intend to buy a car between March 2008 and August 2008 - almost one million fewer than the preceding six-month period. It reveals that £47.5 billion will be spent on purchasing cars over the next half-year, representing an £11.1 billion decrease on the previous September 2007 to February 2008 figures. Steven Baillie, head of loans, Sainsbury’s Finance said: "It is difficult to pinpoint exactly what is behind this decrease and could be due to a mixture of factors such as concerns around much-publicised economic pressures or environmental anxieties. "Indeed, our research indicates that the overall cost of motoring, everything from servicing to insurance and fuel has increased by ten per cent in the last three years." Meanwhile, Motorpoint, the car supermarket, appears to be bucking the trend, with above average sales