It's quite easy to get a professionally accredited car inspection for used cars in the UK. It doesn't cost a lot, and it means the buyer regains complete bargaining power.
Of course, it isn't economical to do this for very old cars, or for a lot of cars.
http://www.theregister.co.uk/2007/05/29/william_davies_ask_v...
Ask.com's terribly misguided advertising campaign.