New figures from the Society of the Irish Motor Industry show that 5,955 new cars were registered in May. This compares to 1,741 in May 2020 and 6,320 in May 2019.
A total of 61,147 new cars have been registered so far this year.
This is up almost 18% compared to the 51,879 new cars registered the same time last year but down 23% on the 79,350 cars registered in 2019 when car dealerships were fully open.
SIMI said that 6,032 used cars were imported in May, compared with 858 imports the same month last year, a decrease on the 9,347 imports in May 2019.
Year to date used imports are up 62.63% on 2020 but down 33.15% on 2019, it added.
Meanwhle, light commercial vehicles (LCV) saw an increase of 2,316 registrations compared to May 202's figure of 500 and 1,717 for the same month in 2019.
Year to date, 16,040 new LCVs were registered - a 60% increase on last year's 10,000 and a 10% rise on the 2019 figure of 14,570.
Today's figures also show that 541 new electric vehicles were registered in May compared to 147 in May 2020.
So far this year, 3,952 new electric cars have been registered in comparison to 1,847 on the same time in 2020.
Electric Vehicle and Plug-in Hybrids and Hybrids continue to increase their market share, with their combined market share now over 23%.
The SIMI figures show that the top five selling car brands in May were the Hyundai Tucson, the Toyota Corolla, the Toyota RAV 4, the Ford Focus and the Skoda Octavia.
The top five car models in May of this year were Toyota, Volkswagen, Hyundai, Skoda and Ford, while the top selling car in May was the Hyundai Tucson.
SIMI Director General Brian Cook said that new vehicle registrations for May were "encouraging", with strong growth in both the passenger and commercial vehicle sectors when compared to last year.
But he added that new car sales year to date are still 23% behind pre-Covid 2019 levels.
"The re-opening of car showrooms to customers and the expected boost to consumer spending has allowed for the completion of deals previously in the pipeline and sees retailers optimistic for both new and used vehicle sales for the balance of this year and into 2022," Mr Cooke said.
"It is hugely encouraging to see the increase in the sale of Electric Cars and Plug-In Hybrid Electric Vehicles (PHEVs), with Electric Vehicle sales for the first five months of the year close to the full year volume for 2020, and further growth is expected as the year progresses," he said.