In Florida, there is also the question of illegal aliens, in large numbers. Many will buy a low cost vehicle and never register it, as they don't have a permanent address or even a drivers license, issued here in the US or Canada. Most of these vehicles also don't have the required liability insurance. With all the laws concerning PC, (probable cause) for an officer to stop a vehicle, an expired tag, is considered an acceptable PC for a stop. No profiling is allowed these days, by any one other than the customs and other border officials.
Another issue that Florida seems to be getting concerned about are part year residents, voting here in person and in their old state, by absentee ballot. If they scan an out of state tag, and then check the voters registration lists and find the same owner on both. That person should have a problem IMHO.
Florida seems to have few if any concerns with out of state visitors driving on out of state or out of country tags, property owners or not, just so long as they don't try to claim homestead exemptions or vote in Florida and elsewhere.
