Lol....... i WAS supposed to have my dad's Xantia handed on to me when I reached 17, as it would then be old enough for him to be replacing it.
Plate? P 174 JNR
(Family initial, what my age would have been, "for junior" hehe)
'course, what with separation (and i assume divorce, though no-ones ever officially told me), loss of job, several instances of employment and housing BS etc................. the sod's still driving about in it to this day!
Not that I mind - its a bloody 2-litre slushbox automatic with that fun-cancelling air suspension and a bugger for parking and reliability. Just would have liked the plate.
Now I'm going off to take a quick peek at Newreg.com, who's ad I saw in a service station convenience last night. Looks like they've got a handy feature where you type in your name, or anything else of relevance, and it generates legal letter-number combos that can spell it out for both old and new plates. Could be awesome.
EDIT: No, it's crap, it's only for people who haven't the brainpower to think of their own selection from the standard lot. It actually
still only searches the DVLA list and is therefore about
as useful for my particular quest as a bag of spanners. Damn. Will have to call DVLA directly and ask them What The Hell Is Going On?! once I have a car new enough to have a T-plate on it. Who's clever idea was it to only offer 400, 444, then 500? Like, maybe I'm a football manager who'd like a "442" on their plate...
) - and I never bought it 
regreted not getting it but not too bothered now.