New vehicle sales are in decline after more than a decade of growth in a sign consumer demand is further softening.
According to the Motor Industry Association (MIA), sales were down 4.5 percent in August compared to the same month in 2018, the fourth month in a row of year-on-year decline.
In the eight months to August, sales were down 5 percent on 2018, meaning 5400 fewer vehicles were sold during that time.
"Growth has disappeared from the 2019 market and we are expecting an out turn for 2019 at about 6 percent below 2018 levels," MIA chief executive David Crawford said.
Mr Crawford said the market had softened more sharply than the industry had anticipated.
"With the population growing you'd expect new vehicle sales to continue to remain strong but I think people are a little bit uncertain about the economic direction with issues around the world affecting people's confidence."
Notable falls included light commercial vehicle sales, which dropped off by 10 percent in August.
"When the sales go down, that indicates that the light trade sector and the farming sector are starting to tighten their belts, they hold on to their vehicles a bit longer."
"We think this is an indicator of some of the slightly tougher times happening in the commercial sector," said Mr Crawford.
The MIA believed the soft patch would persist for several years to come and the industry would need to plan accordingly.