Enlighten me, what is a 57 plate?
It's an overly complex UK thing that the government introduced at start of millenium - many UK folks still don't get it!
The current UK registration has two letters, a two-figure age identifier, a space and then finally three letters.
This format started in 2001, and essentially any new car registered after March and September in any one year will have corresponsing two figure age identifier. The first of these numbers (0 for March or 5 for September at the moment) indicates the time of year, whilst the second of these numbers will indicate the year (currently 7 for 2007). So a car with number plate AB 07 DVL will have been registerd within the 6 month period March 2007 - end August 2007. AB 51 DVL (see attached photo for format) will have been registered between September 2001 to end of Feb 2002.
The 5 will change to 6 in 2010 and to 7 in 2020 and so on until 2050 when the format may be reversed to extend the format another 50 years. Hopefully the attached photo helps.
So a '57 plate' means registered after 1st September 2007 but before March 2008.
Incidentally, the first 2 letters iindicate the part of the country that the car was registered (e.g. GN, GL, GF, GJ are all near Maidstone/Canterbury). The final 3 letters are just random, but unique to the vehicle to which they are assigned.
The Government keeps back special numbers for sale (e.g. XX 57 AUD) and as a means of boosting it's coffers even further).
Confused yet?