Toyota was the most popular make of new car
Figures show the number of new cars licensed here in July fell by 2.7%.
The Central Statistics Office (CSO) says 20,743 new private cars were licensed for the first time last month.
That is a decrease of 2.7% compared with July 2017.
A total of 8,202 used cars were licensed - representing an increase of 7.9% on the same month last year.
In the first seven months 2018, 103,780 new private cars were licensed - 4.5% less compared with the same period last year.
The number of used vehicles licensed rose by 11.3%.
The CSO says Toyota (2,287) was the most popular make of new car licensed in July.
This was followed by Volkswagen (2,240), Hyundai (2,160), Nissan (1,644) and Ford (1,526).
Together, these five makes represent (47.5%) of all new private cars licensed.
In the first seven months of the year, over half (54.0%) of new private cars were diesel, while 94.8% were in the A/B CO2 emissions bands.
There was a 10.5% increase in the number of new goods vehicles in July, compared with the same period last year.
In the first seven months of the year, 0.8% of imported private cars licensed were less than a year old - while 2,955 were 10 years or older.