New car sales rose 28% in September but are 7% lower in the year to date when compared to 2012, according to figures from the Society of the Irish Motor Industry.
More than 3,100 cars were sold in September, according to SIMI, almost 700 more than in the same month of 2012.
Car sales in July, August and September have been boosted by the introduction of the half-year registration system, however improved sales in the past three months have not made up for poorer sales between January and June.
There were 76,717 cars sold between January and September of last year; 6,000 more than in the first nine months of 2013.
In September of this year, Volkswagen remained the most popular make of car last month, while the BMW 5 Series was the best-selling car model.
Almost 73% of cars sold so far this year have been diesel, down slightly on the same period of 2012, while 61% came within the A tax band.
Director general of SIMI Alan Nolan said 2013 has been the second worst year for car sales since 1993 despite the introduction of the dual registration system.
SIMI is calling on the Government to introduce a car “swappage” scheme in the upcoming Budget to help boost sales, which would give buyers a €2,000 VRT refund on a new car if they trade in a model that is at least six years old.