New car sales fell back against last month, dipping 22.2% compared with the scrappage-enhanced figure for October 2009, it has been announced.
A total of 131,495 new vehicles were registered in October 2010, the Society of Motor Manufacturers and Traders (SMMT) said.
The Government's car scrappage scheme had greatly influenced the October 2009 total, taking it as high as 168,942.
Despite the big dip in sales last month, registrations for the first 10 months of 2010 have reached more than 1.76 million - 4.8% up on the January-October 2009 figure.
The SMMT said that further declines were likely in the remainder of year, but that the 2010 year-end total was likely to be just over two million units, up 1.5% on that of 2009.
SMMT chief executive Paul Everitt said: "There was a significant fall in October's new car registrations, reflecting the impact of the scrappage scheme at this time last year and some deterioration in consumer confidence.
"The industry expects the coming months to be challenging with slow, but steady, economic growth feeding through to improved confidence and demand during 2011."
The decline in October 2010 was the fourth successive month of falls in sales, with the dip of more than 22% the steepest since May 2009.
Diesel car registrations rose 3.8% last month, with diesel's share of the market climbing to a record 54.7%. This is almost 14% higher than a year ago when demand for small petrol cars was vibrant through the scrappage scheme.
These were the top-selling models in October 2010: 1. Ford Fiesta; 2. Volkswagen Golf; 3. Vauxhall Astra; 4. BMW 3 Series; 5. Ford Focus; 6. Vauxhall Insignia; 7. Vauxhall Corsa; 8. Nissan Qashqai; 9. Mini; 10. Renault Clio.