Copy of licence most times, sometimes just visually check -BUT everyone customer fills in their details on test drive form, I also put reg no , make , model , sates, times so if anything ever came back I have record with their signature - also includes their PX Car or car they came in ! I've had 2 sets of plates for years - well worth it for me , times when you 2 sets wanting test drives makes life easy and saves others having about waiting ! Test drive - no plates get if it gets caught classed as no tax , possible back duty? insurance issues maybe ? I cant upload the form but pleasure to email it if it helps ?