Always ask for ford discount,9/10 they just ask your FIN number,which can be pretty much any 5/6 digit number.
I'm still using mine 4 years after I left!!!
Or,if you know someone who works in a ford/landrover/jag factory just ask them for thief card.
Most places will knock 20% off if you say your trade,had one place try it on when I had my business so I went elsewhere.never got asked for any proof at all.