Thailand's car shipments in April stood at 67,114 units, down by 7.52% year-on-year, marking the lowest volume in 24 months.
The dip was attributed to a contraction in every region except Oceania and the Middle East, says the Federation of Thai Industries (FTI).
The value of exports last month stood at 35.6 billion baht, down by 3.02%.
Surapong Paisitpatanapong, a spokesman for the FTI's automotive industry club, said the April shipment contraction was the result of higher volume in March, some 117,708 units, the highest tally in 18 months, because there were many holidays in April.
"The Oceania market picked up for the first month in 2019 while the Middle East gained because of rising crude oil prices," he said.
The club reported shipments in the first four months totalled 366,955 Thai-made vehicles, a drop of 0.23% from the same period last year, and export value stood at 185.2 billion baht, down by 2.46%.
For local sales, the market in April stood at 86,076 cars, up by 8.7% from the same month last year.
Mr Surapong said the overall economy in Thailand saw better sentiment with GDP growth and higher consumption.
New car launches in the Thai market and many auto showcases have stimulated motorists to replace or buy new cars.
"New megaproject investment measures to support low-income earners and tourism spending are key to driving the economy and the car market," he said.
The market during January to April stood at 349,625 cars, up by 10.5% from the same period last year.
With sales and export sentiment, overall car production in April totalled 150,242 units, up by 11.5% thanks to the output for pickups and passenger cars.
But April output contracted by 24.4% from March because of fewer working days.
Thai-made car production stood at 711,729 units during January to April, up by 5.52% from the same period last year.
The club reported Thailand's motorcycle production during January to April totalled 843,888 units, down by 1.38% year-on-year.
Local sales for the period stood at 582,454 motorcycles, down by 0.7%.
Motorcycle exports in the first four months rose by 8.68% to 334,209 units.
The value of motorcycle shipments for the period totalled 24.5 billion baht, up sharply by 20.9%.