Figures released from the SIMI (Society of the Irish Motor Industry) show that new car sales in February were down 8% on February last year.
For the year, sales are down 15%.
HCVs (Heavy Commercial Vehicles) were up 16% in February, while LCVs (Light Commercial Vehicles) were down 18% over the same period.
Brian Cooke, Deputy Director General, SIMI, said: "While still down on last year, the fall in February was significantly less than it had been in January.
"We weren't expecting any significant boost from the new number plate system in year one, but at least people now understand that the new system will be continued in future years and the misconception that it was for this year only has dissipated...
"We still, however, expect the new registration plate to take some time to take hold, and hopefully it will continue to create interest as more and more of the new plates are seen on the roads.
"Clearly sales in March will be closely watched as the first quarter will be crucial as to how the year pans out...
"On the used car side, feedback from retailers is that there is increased activity in this sector and hopefully this improvement will continue as the year goes on."