Car looks good.
Wondering about the red asterix on the rear and on the bonnet? I am unfamiliar with this - whats it for?
As regards the door crest - I am unaware to what extent you have researched the door crest situation (no doubt quite thoroughly, I would guess!! ) but have you seen or considered a crest similar to that one which Ford use for their demonstrator vehicles?
It is simply the standard English police crest with the wording 'Ford Police Demonstrator (Vehicle?) around the central part of the crest where the 'Anyshire Constabulary' wording would normally go. It looks convincing enough from a few feet away, but that is a double jeopardy, I suppose!
I have tried a quick google to find an example but thus far, without luck.
HtH
B