New car registrations in Germany fell 18% last month over September last year according to the automobile federation. However, the latest fall, the 10th in a row, was slower than the pace of recent months, when drops of around 30% were recorded.
Previous months have been affected by a comparison with 2009 which was boosted by the German government scrappage scheme which ended last October.
German exports were up 5% in September with a total of 3.1m vehicles sold abroad since the beginning of the year.
The VDA said that German manufacturers had been able to post increases in foreign markets since August 2009. New car sales in Spain fell 26.9% in September and were down by 18.9% in Italy and 8.1% in France.
The European figures contrasted sharply with data released on Friday in the US where automakers posted significant gains in September sales from depressed 2009 levels.