More than 4,000 Irish motorists bought 2011-registered vehicles in the first week of January, a 31% rise on sales for the same period last year.
According to statistics provided by Motorcheck, 4,115 new cars had been registered by the end of last week, while 383 new commercial vehicles were separately registered.
Last year, 3,140 vehicles for personal use were registered in the same period.
Meanwhile, the highest number of new-car registrations in recent years was recorded in 2008 when 7,850 new cars were bought in the first week of January. The next year saw a significant drop to 2,590.
Despite this year's increase, Motorcheck managing director and director of Benchmark Fleet Services Shane Teskey said last week that 2011 would not see any marked improvement in the Irish motor industry.
"It has to be taken into account that at this time last year we were suffering majorly under a bout of very bad weather and that did not help matters. While the general amount of sales this week is quite good for newly registered vehicles, I don't believe that 2011 will see any major improvement in car sales.
"The industry predictions are that it is going to be another difficult year for car dealers and it is still extremely difficult to shift cars off the forecourts."
According to Teskey, consumer sentiment is still low and sales are unlikely to pick up throughout 2011.
It is predicted that over 70% of all new cars bought this year will be diesel vehicles.
"This is a major turning of the tables compared to a few years ago, when almost 70% of vehicles were petrol. This change is because of the soaring price of petrol and the fact diesel is still considerably cheaper," said Teskey.