The numbers of cars built in the UK fell again in January, making it eight consecutive months of lower output, according to the Society of Motor Manufacturers and Traders (SMMT).
The SMMT said overall production was down by 18.2% while production for exports fell 21.4%. Slowing demand for cars in China and the EU was the core reason behind the results.
The number of cars built for China was down a huge 72%, while it saw a 20% drop for the European Union.
However, the SMMT also said a "significant part" of the figures came from manufacturers phasing out older models.
SMMT chief executive Mike Hawes added: "The industry faces myriad challenges, from falling demand in key markets, to escalating global trade tensions and the need to stay at the forefront of future technology.
"But, the clear and present danger remains the threat of a 'no deal' Brexit, which is monopolising time and resources, undermining competitiveness."
The SMMT's announcement adds to growing negativity in the car industry in the UK ahead of Brexit. Earlier this month, Japanese carmaker Honda said it will close its factory in Swindon, putting 3,500 jobs at risk. Just days before that, Ford threatened to pull out of the UK if Brexit went ahead in a no deal scenario. And earlier this year, Nissan scrapped plans to build its new X-Trail model at its plant in Sunderland, while Jaguar Land Rover announced announced 4,500 job cuts.