I've never seen the point of personalised car registrations, just extra cost and makes your car easier to find if someone has a grudge against you, besides which they're much less entertaining than the unintentional words which can be made from the current and old type sequential plates.
We used to encourage our children (8 + 11) to make the best word from passing numberplates until the youngest informed my wife she'd seen PORN again (P**ORN) to which her older brother said "that's nothng, I've seen a ******! (W**NKR).
We don't play that game anymore.