August sales data shows a subdued performance for some of Volkswagen's key models in the midst of a flat Australian car market.
The European car maker has attracted significant negative publicity this year, and is in the midst of a recall of some models of its cars.
The recall was announced in June after an inquest into the death of Melbourne woman Melissa Ryan raised serious public concerns about some Volkswagen vehicles.
The inquest heard that in January 2011, Ms Ryan's car appeared to suddenly lose power before it was hit from behind by a truck on the Monash Freeway.
Since then, scores of drivers have come forward describing instances where their cars have suddenly lost power.
Volkswagen is in the process of recalling various models of its cars, along with some Skoda and Audi models fitted with direct shift gearboxes (DSG).
The new vehicle sales data for August obtained by the ABC shows sales of the most popular model, the Golf, were down 9.6 per cent in August, with a fall of 12.6 per cent so far this year.
The company sold 1,361 Golfs in August, compared to 1,505 in the same month last year.
Jetta sales were down 22.2 per cent in August, falling 6.3 per cent in the year to date.
Sales of Passat cars fell 10.2 per cent in August, and have fallen 33.5 per cent for the year to date.
Volkswagen sells 22 different models in Australia, and total sales across all models rose 3.7 per cent for August.
The Tiguan posted a 71.4 per cent increase, with 689 vehicles sold in August compared to 402 last year.
Sales of the 4x2 Amarok, Multivan, Polo and Touareg cars all increased in August.
The Federal Chamber of Automotive Industries says overall, the industry took a hit in August with car sales down 0.2 per cent compared to August last year.
During the month 93,336 vehicles were sold and the Mazda 3 was the top selling vehicle with 4,188 sold.
A spokesman for Volkswagen says he is pleased with the sales result for August.
"Regarding our sales, we are pleased with the August result as we saw our sales grow against a drop in the overall market," he told the ABC via email.
"We are progressing well with the recall.
"It is still anticipated the majority of vehicles will have repair done by the first quarter of 2014; however, there are always customers who choose not to bring in their vehicle for the free repair."
The Golf sales figures represent a recovery from a poor result in June, when sales were down 55.8 per cent for the month.
Tiguan sales have had a big turnaround from their June result, when sales were down 49.1 per cent.
Volkswagen drivers have continued to contact the ABC to share their experiences of their cars suddenly losing power.
It is expected the Coroner will deliver her finding on the cause of Melissa Ryan's death by the end of the year.
The coroner has written to the Department of Infrastructure and Transport and Volkswagen to assist with her investigations into the case.