just stumbled upon this. it would appear you can do a free on-line MOT History check on any car providing you have the registration and current MOT certificate or your log book reference:-
http://motinfo.direct.gov.uk/interne...ry-Request.jsp
I just did it and it shows some MOT history. Firstly it shows if the current MOT certificate is genuine. Then it shows past MOT History including garage name and phone number where the tests were done, what it failed on, any advisories, or just "Pass" if it went through with no problems.
It also shows recorded milage which could help you spot a car thats been clocked.
It even showed on my car that it used to have an "L555" registration.
Definately worth adding to your favriouts. next time you buy a car, its a free check you can do and any genuine seller shouldnt have a problem giving you the registration and MOT certificate number so you can do the check