The Society of the Irish Motor Industry (SIMI) has announced that new car sales fell by 22% in April, compared to the same month last year.
Year to date sales show a 7% decline.
The figures reflect the decline in showroom footfall around the country and lack of retail activity, according to the SIMI.
Alan Nolan, Director General of the SIMI said: "While the industry is still trying to drive sales, the reality is that the peak selling period of 2012 is now over. Because of the seasonal nature of car sales, sales will continue to decline month on month for the rest of the year."
According to the SIMI, 80% of all new cars are sold in the first half of the year.
Mr Nolan said: "Every year, we see the same pattern; a spike in car sales in January and then a decline, month on month."
"What this means is that staff who are taken on for the busy first quarter, often have to be let go mid year because of the lack of activity throughout the rest of the year."
The CSO recently revealed that in the first six months of 2011, 1,300 jobs were created, however, in each subsequent quarter of the year, there was a decline in employment.*
The SIMI wants the Government to introduce a second registration plate mid-year. This would create a second sales peak and would maintain and stabilise jobs.
"If there was, like in the UK, a second registration plate in June, the industry would now be gearing up for another busy sales period. But because of the current system, retailers now have to wait until next January, another eight months, for any potential improvement in sales.
"A second registration peak mid year would not only assist the Motor Industry but would increase employment, stabilise existing jobs, increase tax revenues for the Government and also add value to motorists's trade ins."
Currently, a car purchased in December is valued the same as a car purchased in January, a second plate will add value to those bought later in the year.
"Experiences in other markets indicate that the change in registration plate will generate extra sales and extra Government revenue. Applying this to Ireland, we would see Government revenues increase by over €20m in the first year of the change alone."