fair comment.

I suppose I look at them as a small part of the cosmetics.
If you care about your car as a design or 'artistic' thing (note, not 'fashion') which, by some twist of my psyche, I do, then a number plate can have an effect on the looks.

You missed the 4th category (which we belong to).

Owners initials.

So one car will be MIST DG and the other WISH DG
It's good when you and your wife have the same initials
And I can't wait for a joint photo!

And these plates cost me about the same as a top-end detailing session on the car - or about the same as a set of 6" component speakers. Or, for the Jag, around 0.5% of the cost of the car... so things are relative...

And the 5th category - bloody expensive words - like
BAD 130 Y
which I saw on a mercedes once a long time ago.

The [DBG]AZ plates - yep, ugh.