I want one! We have several American plates, the ones with state mottoes on, but even if we could put UK registrations on them they'd be illegal. No custom plates in the UK - you can buy regular plates - from the Government, natch - with interesting combinations of numbers/letters, but they all have to conform to the legal requirements and the year number is always a part of the set so you're stuck with 06 ( or 66 depending on which half of the year your car is registered in) or whatever. Some people keep old numbers ("cherished numbers", in official parlance) say with their initials and a number - someone I know has C1 and his three initials. These you buy from private dealers - the price can be up to £15.000 for rare ones and the first-ever plate, A1, would be millions, I should think. You can put them on your car, but when you sell it the original official plates have to go back on.
No custom holders either - our plates are stuck on the car - ? screwed on? I've never looked.