An MOT certificate does not mean the car is roadworthy, it was only technically roadworthy at the point the MOT was issued. Saying that, I have sold plenty of cars which, when the handshake occurs, have a short MOT. My perspective is that it is up to me to make sure the car is roadworthy before the car leaves or any money changes hands. Therefore all my cars are MOT'd before they leave the premises. The deal I did yesterday was on a car with a lapsed MOT, just a 2014 car that had been hanging around, nothing sinister. Within a couple of hours, the MOT was done and everybody is happy.