Front Number Plates (again ... sorry)

The local police are trying to stop the (very common) application of black and silver registration plates on many of the modern cars over here. As result, I shall have to reluctantly change the modern "daily" to white/yellow reflective.
However, I have toyed with the idea of applying black/silver to "Gina". Here, legislation permits black/silver to pre 1984 cars (UK i think, is 1972).
I saw a 3X8 series advertised in this months Classic and Sports Car, sporting a sticky, vinyl plate on the bonnet, as per fezzaphils' E Type (discovered in a thread whilst searching for info). Whilst this doesn't look too original, am I correct in thinking that front number design would differ all around the world, therefore originality wouldn't suffer ?
I recall reading very recently, info relevant to the specific legal requirements re letter size, colour, car design etc. - Could somebody point me in the right direction, or substantiate the above. I recall also, someone carrying a copy of a letter / legal doc.(or similar) to deter mr. plod from ticket allocating.
A much smaller vinyl plate could easily fit across the front lower valance, without obstructing air flow to the radiator. This would probably prove more suitable than the bonnet option .... wouldn't it ?

Why do police forces insist on white/yellow ? One theory is, plates are required to be uniform to allow the "reading" of plates to discover tax, insurance details etc etc. If so, are classic car owners exempt from all this stuff ? (and why?)

comments please.
cheers, d
(land without speed limits or cameras ! ... ha ha)

 

thanks G, .... looks very complicated.

No! (thank you) .... we have the oldest surviving parliament in the world, and our own currency. (did i mention no speed limits or cameras ?)
On the down side, diesel is currently 99.9 pence per litre.
Missus looked to enjoy herself earlier, si ?

I would remain grateful for any further info/advice on the regn. plates.

cheers, d