If your vehicle does have a marker they wont tell you anyway, i was pulled 6 times in two weeks, this was in Lincolnshire, Yorkshire and Nottinghamshire and the times varied between morning/afternoon and early morning, and at no time was i doing anything illegal, i asked why i was pulled over each time politely and was told once i was driving too slowly in Notts (doing 50mph in a 60mph at 1am) and breathalised(i dont drink), once picking up a dog at lunchtime when they went over my vehichle (all fine, I was told i was pulled as i was in Yorkshire due to 4x4 thefts), i was also pulled in Lincs(