Car sales in Co Mayo so far this year are down almost 9% on this time last year.
Latest figures from the Society of the Irish Motor Industry shows total new car registrations for Co Mayo to date in 2019 are 1,182 - down from 1,291 this time last year -that's a drop of 8.4%.
In Galway, there's a drop of over 10% in new car registrations so far this year, and a 13% decrease in Co Roscommon.
However, the number of imported used cars is up almost 10% nationally, while new electric vehicle registrations continue to grow.
So far this year, 1,437 EV cars have been registered across the country - which has surpassed the total number for the whole of 2018.
The society's director general-designate Brian Cooke says new car sales are being dampened by Brexit uncertainty, while the increase in VRT on new cars for 2019 has also had a negative impact.
He says the one positive in the market is the increase in the number of new electric car registrations.