My best 'pupil' was a chap, mid 30's,big tough chap. wanted 8 lessons and a test, paid up front, cash. Radar flapping when i found out he had to do an extended test!! which meant he had been banned at some point. Prior to becoming a driving instructor i worked for plod as a 999 dispatcher, so i had a word with some friends. Turns out this chap had been the getaway driver in a robbery, led the police on a lengthy pursuit before dumping his passangers and then crashing into a police car !!!! I was his first port of call after getting out (turns out i had got his lads girlfriend through her test). Nicest bloke ever, wonderful driver, very safe. passed with no errors, so confident he left a thank you card under the drivers seat before starting the test !!!