Last month saw a 14.6% drop in the number of new cars licensed around the country, compared to the same month last year.
CSO figures released today showed that 10,581 were licensed in March 2012, compared to 12,390 in March 2012.
Goods vehicles were only slightly down, recording a drop of 2%, from 1,179 to 1,155.
Overall, the figures show the total number of all kinds of vehicles licensed was down from 19,307 to 17,171 - an 11.1% drop.
Of the 10,581 new private cars licensed, 2,568 (24.3%) were petrol and 7,705 (72.8%) were diesel.
The highest number of new private cars licensed in March 2012, classified by make, was Nissan (1,410) followed by Volkswagen (1,257), Toyota (1,140) and Renault (947).