People in Northern Ireland are the least likely in the UK to name their cars, research showed.
Across the UK women were almost twice as likely to do so as men.
Most were aged between 55 and 64.
The make, model, colour and general look of the car were the common reasons given for the choice of name, with Fords, Vauxhalls, Toyotas, BMWs and Hyundais being the makes of vehicle most frequently given a name.
The research was carried out by the Driver and Vehicle Licensing Agency (DVLA).
DVLA personalised registrations sales manager Jody Davies said: "We sold DOR 1S, DAV 3S, HEN 2Y and HER 81E in the past, as well as personalised registrations where the meaning and significance seems much less obvious.
"It's no surprise to find that people want to say something about their car in this way - whether the name is something personal to them or bit of fun that they want to share with others."