With the overall UK new car market down 2.3%, Saab saw its registrations rise by almost 70% compared to the previous year.
With the exception of Aston Martin, Saab was the fastest-growing car brand in the UK in August.
Year-to-date sales, at just short of 17,000 cars, were 42% higher than the 11,865 cars it sold in the corresponding period in 2004.
Demand for the 9-3 Sport Saloon fuelled the August surge in new car sales with registrations of that model increasing by 168% last month compared to the previous year.
Jonathan Nash, Saab Great Britain managing director, said: "2005 has been a superb year for Saab in so many ways. Not only have we achieved phenomenal year-on-year sales growth for every month of 2005, compared to 2004 – which was itself one of Saab's best-ever years in the UK since imports began in 1960 – but this growth has come from every single model across the Saab range."