i think, we dont have an extra thread for police-cars over her, so i am opening one.
in my license plate-collectors-forum i found that link:
http://www.policecars.hu/

yes, its in hungarian language -which probably the most of us don't understand, but if you want to see a plenty of pics, click on "english" and then "pictures". there are a lot of police-cars from other countries, too.