Figures released this week by the Society of Motor Manufacturers and Traders show registrations of fleet cars are up 6.7% in September 2010 compared to the same month last year.
However, new car sales in general were down 8.9% for the third month in a row.
The fleet car market occupied 43.6% of overall car sales in September, a figure up 6.4% on last year.
The top five fleet cars with regards to September 2010 sales were: Vauxhall Astra, Ford Fiesta, Ford Focus, Vauxhall Insignia, Ford Mondeo.
More than 1.6 million cars have been sold this year, 7.8% more than 2009. In total, the number of sales has risen over the past 12 months by 14% yet since the end of the scrappage scheme, three months ago, demand has dropped by 11%.
Research by the SMMT is predicting a total of just over two million total car sales at the end of 2010, slightly up on 2009.
The VAT rise in January could also positively affect demand towards the end of the year, with buyers choosing to purchase before the end of 2010.