Car manufacturing in the UK fell 4.9% in May with 99,280 units produced, according to figures released by the Society of Motor Manufacturers and Traders (SMMT).
Commercial vehicle (CV) output fell 5% in May to 10,205 units.
However, car manufacturing is up 4.6% to 542,816 units over the first five months of 201,compared to the same period last year.
But the CV market has suffered with production plunging 5.5% in the January to May period to 50,995 units.
With the fall in commercial vehicles being produced, van insurance providers are likely to be keener than ever to offer cover for newly built models.
Engine production rose 4% in May to 214,218 units and was up 5.6% over the first five months of this year.
Recent announcements made by Nissan and BMW on major investments in UK plants have boosted the motor industry.
Paul Everitt, SMMT's chief executive, said: "Recent announcements demonstrate the commitment being made by global vehicle manufacturers to the UK motor industry. These will secure future production and jobs, as well as opening up new opportunities for the UK-based supply chain."
© Press Association 2011