The embattled car-maker saw its share of the UK market fall to 7 per cent in November - the second worst monthly figure on record - as uncertainty over the future of the company took its toll on sales.
Walter Hasselkus, the chairman of Rover, resigned earlier this week, taking the blame for mounting losses and the crisis which brought its Longbridge plant in Birmingham to the brink of closure.
Rover was comprehensively outsold in November by the market leaders, Ford and Vauxhall, but also trailed Peugeot and Renault and only just squeezed in ahead of Volkswagen in the sales table.
Last month Rover sold 10,704 cars compared with 16,465 in November last year and did not have a single model in the top 10 best sellers, according to figures from the Society of Motor Manufacturers and Traders. In October, its market share hit its lowest ever level of 6.56 per cent and for the first 11 months of the year it is at a low of 8.7 per cent.
BMW, Rover's owner, only agreed to keep Longbridge open and pump pounds 400m into the plant to build a new Mini after unions accepted a new labour flexibility deal.
A Rover spokesman said media speculation about the company had not helped. "Uncertainty about the future of the company undoubtedly caused a slowdown in showroom traffic," he said.
But he said Rover's market share would have been down last month year- on-year in any event.
"We would have been in that position anyway because we have fewer models on sale and we have walked away from the low-margin rental end of the market."
Rover has stopped production of the Rover 100, which sold 31,037 units in the first 11 months of last year compared with 8,335 in the same period this year. It has also ceased manufacture of niche models like the Rover 200 coupe and the 400 tourer.
The spokesman said that Rover had budgeted on UK sales falling this year although he conceded that the actual figures were lower than forecast.
The company is pinning its hopes on the new executive car, the R75, which goes on sale next spring. Rover hopes to sell more than 100,000 units a year and is pitching the car against the likes of the Audi A4 and Alfa Romeo 156.
But motor industry analysts fear that with a starting price of around pounds 19,000 and a top price of pounds 27,000 for the 2.5 litre V6 engine version, the R75 is overpriced.
The respected Car magazine believes that the R75, a retro model reminiscent of Rovers from the 1950s and 1960s, will also compete head-on with the BMW3-series made by Rover's parent company.
Garel Rhys, professor of motor industry economics at Cardiff University Business School, thinks the R75 is pounds 2,000-pounds 3,000 overpriced.
"If it does not sell in sufficient quantities next year, then Rover has a real problem," he said.
Total new car sales last month, at 152,314, were virtually unchanged on a year ago but the share taken by British-built cars fell to just 32 per cent. Sales for the year to date are up by 3 per cent at 2.15 million.Reuse content