I never understood vanity plates. When on the road ‘tis best to be as anonymous as possible.
My vanity plate is my ham call sign. It doesn't cost me any more than a normal plate and it identifies me as an emergency responder. I got stopped once because a cop didn't like how I handled a stop sign, and my tag was expired by a month. He asked me if my tag was my husband's call sign and I said, no it's mine. He let me go.