The system worked because it was the duty of the AA (and RAC) patrol man to salute any passing car which was displaying an AA/RAC badge - as a courtesy to its members. However, if the patrol man did not salute the passing member, the driver was asked to stop and consider the reason why the patrol man failed to salute. What a lovely system - worth paying your membership even then!!
My Dad, who was a staunch RAC member, used to have a cartoon, from Punch or similar which showed an AA man and an RAC man saluting their respective members and each pulling the other off their patrol motorcycles because in saluting they had managed to lock their arms around one another - Ho ho
