Car giants including Toyota, Fiat and Ford have seen steep falls in European sales, underlining the impact of last year's car scrappage schemes.
In September, new registrations of Fiat cars were 21% lower than the same time last year, when incentive schemes boosted sales.
Toyota also saw a 21% fall, while Ford car sales were down 20%.
Overall, registrations of new cars in Europe were 9.2% lower, with 1.26 million new vehicles registered.
The year-on-year fall is the sixth decline as many months, with all major European markets down.
In the UK, new car sales were 8.9% lower, while France and Germany saw falls of 8.2% and 17.8% respectively.
Spain saw the biggest fall, dropping 27.3%.
Last year scrappage schemes across Europe were rolled out, incentivising new car sales to boost the ailing car industry.