New family cars in the upper-medium category are depreciating in value by up to 60% over the first three years, according to new research from the Alliance and Leicester bank. This is because ex-lease family vehicles are flooding the used car market. Alliance and Leicester surveyed UK cars by size and form-factor category. The survey revealed that all cars except for those in the executive and luxury categories are best bought when three years old, to benefit from low residual values. For upper medium category family vehicles these are currently standing at 39.8% after three years, compared to 47.4% a year ago.