I know of too many people who have bought cars from dealers where the car fails in one or another within the so-called warranty period. The hassles really start when you find that the onus is on you to prove to the dealer that the car he sold you was a dud. The hassles of all that have always steered me to private sales. At least you go into them without any expectations that will be dashed later. As golden boy stated above, the savings from going private more than adequately cover the majority of things that you might not have found during your own inspection of the car. If you're not confident that you can assess a second hand car properly, let the AA or RAC do it for you for a relatively small fee (less than £100 I think).