Where should you buy your used car?

Sarah Coles
scrap cars
scrap cars

Paul White/AP/Press Association Images

The process of buying a used car can be tricky enough as it is. Somehow you need to become an expert on cars, know how to spot the difference between a little niggle and a complete disaster, understand and translate sales patter, and master the art of negotiation in order to hammer out a good deal.

However, all this will be wasted unless you know a little-known rule about buying a used car.