I wouldn’t spend tuppence on a personalised number plate (though I did once own a car whose figures were 666, the number of the beast, and a beast it was). But Duncan Barkes’s damnation of them is WA10VER the top.
I have a nephew whose parents bought him THJ73 – his initials and year of birth. Neither parents nor son show even a hint of ‘pretension, over-indulgence’ – he’s not an only child – or ‘insecurity about their own identity and status’. So why did they do it? My guess is: on impulse, for fun.