New car sales were down almost 9.5% in April when compared to the same period of last year, according to figures from the Society of the Irish Motor Industry.
A total of 6,121 cars were sold last month, according to SIMI, 639 fewer than in April 2012.
There have been 45,581 cars sold so far this year, which is 13% lower than the number sold in the first four months of last year.
In the commercial sector, sales of trucks were down 22% compared to April 2012, but are up 2% for the year.
Sales of vans and light trucks were up 10% last month, but are down 9% so far in 2013.
SIMI’s director Alan Nolan said that the market was currently operating at around half of ‘normal’ levels, which he described as “unsustainable”.
“With consumer confidence and spending still showing no real signs of recovering anytime soon and with much uncertainty among the public sector around Croke Park 2, this has impacted on the new car market."
He said that the price of a new car had fallen as sellers seek to attract customers in, with the average new car now costing 10% less than in 2007.
Of the cars sold last month, almost 14% were made by Volkswagen, which remains the most popular brand in the country. Toyota is second with 9.7% of the market, though this is almost 3% lower than its share in April 2012.
The most popular car last month was the Volkswagen Golf, while the Ford Focus was the second most sold model.