As an Mot examiner i was learnt that if i failed a car that was up early for Mot then im saying its not road worthy as ive failed it for a reason, for example its failed on brakes imbalance, so if its not road worthy then the old mot doesnt stand. If the enforcement stops you and finds something wrong they put a prohibition on the car, your old mot is then no longer valid until you produce your car at the mot centre with these parts fixed. This is northern ireland im talking about. I must ask more questions to see what they say.