question about spring mounted number plate holder



Hi, as I have got a still standard k11 for 2 years and I will look as I will someday have to start "personalise" my K11

I want to ask if these spring mounted front number plate holder are legal to have in the UK

I mean the one you have seen on magazines in J-Tuner on modified cars in Japan, especially at Masamania's site on expressway racing (you can tell by looking at a piece of metal holding the plate together) which fold back when the car is travelling at a cartain speed as I have seen on some and where can you get them from

Also how do you shave off the front plate holder found in all stock bumpers