New car sales in January are down 18 per cent on last year, and the AA says it is likely because of the new licence plate system introduced this year.

New plates now come out twice a year, with 131 plates issued in January, and 132 registrations on new cars from July.

It is to spread new car sales throughout the year, because under the old system 80 per cent of new cars were being sold in the first four months of the year.