UK car production fell 11.2% in July compared with last year because of a change in holiday patterns, according to the Society of Motor Manufacturers and Traders.
The SMMT said the traditional annual shutdown started earlier at some vehicle plants.
The seasonal pause in production allows for maintenance and upgrades.
Despite the dip, Mike Hawes, SMMT’s chief executive, said: “The industry remains in a strong position.”
Last month, the trade association said the British car industry had had its best first half of a year since 2008.
More than 911,000 cars have been produced so far this year and domestic demand has grown by 8%.
In July, 9,274 UK commercial vehicles were built, increasing production by 46.3% in July, signalling a continued recovery in the sector.
It has seen production grow by a third this year.
Demand in the domestic market for commercial vehicles was particularly strong, up 137.6% compared with July 2014.