New car sales were nearly 7% lower last year when compared to 2012, according to figures from the Society of the Irish Motor Industry, despite the introduction of the dual licence plate system.
Dealers had hoped the system, which splits the year into two six month-long registration periods, would help sales following its introduction last January.
However this boost failed to materialise, with just over 74,300 cars sold during 2013 compared to more than 79,500 in the previous year.
The new system did have some success in spreading sales out, however, rather than have the bulk of them take place in January and February as in previous years.
In 2013 around 28.3% of sales took place in the second half of the year, compared to just 16.1% of sales in 2012.
Customers still prefer to buy cars at the earliest point possible in the registration period, however, with nearly 39% of sales taking place in January and July alone.
Volkswagen was the most popular make of car in Ireland during the year, making up 12.8% of all sales.
Hyundai was the fastest growing brand, meanwhile, becoming the fourth most popular make with a 7.8% share of sales.
The Volkswagen Golf was the most popular model of car, meanwhile, representing close to 5% of all cars sold. The Ford Focus, which was the most popular model in 2012, was in third place.
Meanwhile, car buyers continued to opt for models with lower emissions, with 61.1% of sales falling within the A band of the emissions-based tax system.
A further 32.7% of sales fell within the B band, leaving just over 6% of sales in band C or higher.
Diesel-fueled models continue to be the most popular choice too, representing 72.5% of all new cars sold, however sales of petrol models did improve slightly during the year.
Meanwhile silver and black remain the most popular colours, chosen in 22.8% and 22.78% of sales respectively.