Right.....speaking from experience here - so believe me! LOL! Tell him to go & get an MOT straight away & take that with him together with the expired MOT - be completely honest with them & make sure he tells them that he had not realised it had expired - you'll prob find that they'll let him off (as long as it aint months & months out of date!) - because you dont get a reminder about your MOT so people often forget apparently!

I got told this by the local police when myself & a friend tried to 'avoid' getting into bother!!