The C1 was first introduced in 2005 (along with the cousin cars, Peugeot 107 and Toyota Aygo, all built in the same factory in Czechia). This example has a personalised/cherished registration. As far as I know, any 1983-series plates with the combination of '123' or '321' were only available as DVLA select registrations, and could only be obtained as a personalised registration.