A thought occurs, has the car been cloned or did a previous keeper cause the problem. Contact the ANPR desk at your regional HQ and get the marker removed. If all the offences occurred before his ownership it will be no problem. If they are still going on get the marker changed to " verify keeper details and VIN" has he got his details for the car registered with DVLA or did he or the dealership forget. I know when I bought my Morgan admin "forgot" to send of the V5. I only found out when I contacted DVLA to put my cherished transfer on.