If you've recently bought a new car, don't read any further! It could lose as much as £500 in the first month, according to figures from RAC Financial Services. Experts also put the average cost of running a new motor at £5,300 per year. However, small models such as the Toyota Yaris - with an annual spend of £3,500 - don't fare as badly as big cars like Renault's Espace, at £8,000.