Don't really have a 'vanity plate' as they're to doggone expensive, but I do have a special Ohio tag with a pix of a lake Erie lighthouse and the 3 number/3 letter setup which is the opposite of normal plates.
I did get a custom license plate bracket made up (engraved) that reads RES IPSA LOQUITUR which means 'The Thing Speaks For Itself"'. Works for me. ZZZ.