This i am a 100% sure of.. you can buy used police Crown Vics from police departments.. they remove all the strobes, MARKINGS and etc, but leave the police interceptor badge..

now, WHY would they sell something illegal?!?!?!?!?!?

in this case, they removed all strobes except the corner ones.. idk why..
http://cgi.ebay.com/ebaymotors/Ford-...spagenameZWDVW