From what information we have found on MOT testing in the UK, the agency responsible for M.O.T is the Vehicle and Operators Services Agency (VOSA). The government's current project is to computerise the MOT test, which should be completed everywhere by March 2006.
The new computerization scheme provides the garage with PCs, monitors and printers that are connected to a central database of vehicle information. Typically the motorist will not notice any difference expect in the format of your certificate but the details of the test will be recorded on the database immediately.
This new system allows motorists to check the MOT status and test history of a vehicle that you currently own or are considering buying. When your vehicle is tested the MOT looks at important components to make certain the meet the legal requirements set forth. But the MOT certificate is not a guarantee of the general mechanical condition of the vehicle as you asked.
If you want more information regarding the MOT you can check with vosa.gov.uk. When you are in need of UK car insurance you can get a quote here with us.