The ones I have all came with cars.
The only one I do like is the one that came on the 100 Coupe S as on the original order form they had requested an "interesting number plate" and the garage issued them this!
Nowadays, the DVLA would be cashing in on this as they don't release low numbers for general issue as it generates waaay too much income for them.
Alex's Piss rat 4motion is S30VVW, and the lad we bought it off got it from the DVLA for about £500. It's spaced to read S30V VW as it's a 30V VW !! Great wooopeee do!!