British cars did not have licence plates until 1903. The government then decided that all cars must be identifiable and invented a system of letters and numbers which were allocated to the car when new and stayed with it until it was scrapped, (but not always).

The political system in Britain divides the country into administrative areas which were known as counties and could have within them cities and large towns which had borough status. Each of these was allocated single letters or pairs of letters starting with A which was London, since the allocations were done in decending order of population. Staffordshire, my home was given E.

Each letter or pair of letters was followed by a number from 1 to 9999.

Since these soon ran out a six digit system was introduced, whereby the single letters were dropped and the pairs of letters were prefixed by an index letter starting with A, so ABC 1 ran to ABC 999 then went to BBC1 and so on. When these ran out the order was reversed so 1 ABC etc.

All the areas registered different quantities of cars so some ran out faster than others and you needed to be a local and a nerd to tell the age of a car.

In 1963 most of the numbers had gone so a 7th digit starting with A was added at the end to signify the year ie ABC 123A would be a 1963 car. When these were running out they were turned round so A123 ABC. Now these have run out so we have a completely new system started in 2001 which uses completely new codes.

To finally answer your question, CE was a code for Cambridgeshire, and the car you saw in the film was the 9519th car in that series.

You can also now transfer registration numbers and buy suitable combinations if available, so my Audi has my initials in its plate.