It feels like Michigan has more custom vanity plates per capita than just about anywhere else.
Why? Michigan's Secretary of State vehicle registration forms include a line for personalizing new plates — something I've not seen in other states. While plenty of states offer vanity plates, they have to be requested explicitly.
It stands to reason that when people are presented with the option up front, many take it.
A growing collection spotted around the state, June 2024 to today — about 200 plates so far, with more added regularly.