here in the UK we often afix the genuine plates to the vehicle but only in the show field...some owners do however afix them permanantly on the vehicle along side the new issued plate...never heard of any problems this side of the pond with Police or MP's...although there is at present an ongoing MOD operation whereas MP's are going around swap meets/military shows etc...and searching dealers who are selling new issue military kit...have heard of a couple of arrests...best regards malcolm