Hence the plates always seen on the Alpina latest demo cars OAL*B5, OAL*D3, etc?
Well, if you call that personalised - then they do exist. But they are not owned by the owner of the car and cannot be sold/traded. It's more that you can pick any free number out of the database and then you get to keep it as long as you own the car.
Someone who lies about the little things will lie about the big things too.