various states
(have already checked the above link to prior discussions).
The home I worked for here in FL had personalized tags on EVERY vehicle, i.e. Farly1 Farley2, 1Farley, 2Farley, DFarley etc. So they didn't use the hearse plate. I have a list somewhere that explains every license plate code in the history of plates in Florida. They are letter prefixes which have are no relation to the type of car. The letter(s) are preceded by the county code (in order of population way back when). Then the rest of the tag is the numerical sequence. A great thing here is that you can use a real license plate that matches the year of your car, and ignores the old policies. They have to physically see the plate in Tallahassee. They won't ok one that has been restored!!! (of course after it's certified no one cares).
In NH I liked the PLUS signs and had them on my personalized KL plate on my sexy Chevy Chevette when I lived there.