In case anyone stumbles across this thread, my mate crashed his car the other day (well a wheel fell off on a roundabout poor fella
) and i immediately went down to check he was ok/control traffic, and when i got there a policeman already had turned up...
Anyway the point of me saying that is that i got speaking to the policeman and asked about displaying these jap plates on the rear of my glanza (and sticking your standard plate in the rear window and having it lit up at night) and his main query was that they have to sit vertically and be visible in the dark (i.e. lit!)... So anyway i've had my UK plate stuck in my rear window and my Jap plate in the recess for 5 months now with no problems!