Shocking new findings show that a third of motorists have driven a car knowing it has no MOT. The Society of Motor Manufacturers and Traders (SMMT) surveyed 1,000 UK motorists and found that, of those that have driven a car without a valid MOT, 67% admitted driving for up to a week before the retest, 24% for up to a month, 7% for up to six months and 2% for more than six months.