VW sales fell 13.9 percent year-on-year in January, following on from drops in October, November and December, after the firm admitted to cheating US diesel emissions tests, prompting the biggest ever scandal for the German carmaker.
Sales of Volkswagen Group's Seat models fell 24.6 percent, Skoda dropped 2.4 percent and there was a modest rise in registrations of Audi models of 1.4 percent.
Total new car registrations rose 2.9 percent to 169,678 cars in January following on from a record high of 2.63 million in 2015, boosted by low interest rates, cheap credit and rising consumer confidence.