Interesting...No, we are not (allowed to be) that crazy. We also don't have the ability to swap a license plate for an alias.
To make the understatement complete (or optional the decadence) I would put "Hi" on the daughter's 12 year old Fiesta („Hi“ as seen in your link, Richard).
Our fun is limited to "buy" certain letters and number sequences ...for 20€....if they are still free. But the letter of the registration office always remains, e.g. K for Cologne, so my 1968 Mercedes has the license plate "K MB 230". But it was great luck that this license plate was just not occupied.

'14 4/4 graphite grey