Have you tried following? We usually send safety and driving standards advice to these people
Driving Instructors Association (founded 1978 and consults with Hendon and DSA) . Membership is open to anyone interested in road safety - not just for ADis and PDIs Our nerd has something to do with these people in his job role in EU.
Contact DIA, Safety House, Beddington Farm Road , Croydon. CR) 4XZ
and
Motor Schools Association of Great Britain (MSA) - this is body which allegedly monitors driving instructors
Think they are based in Stockport - perhaps PeterE knows them?