Jaguar and Land Rover lost sales in the US last month as the pound soared in value against the feeble dollar.
The decline on the part of the two West Midland manufacturers contributed to a dismal month for parent group Ford, which saw itself overtaken by both Toyota and Chrysler in the November sales league.
Jaguar saw its sales fall by 35.2 per cent to 1,256 last month and by 31.6 per cent to 19,130 over the first 11 months of the year.
The company, however, is being saved from a complete sales disaster by the booming success of its XK sports car.
Sales of the Birmingham-built car rose nearly threefold to 324 in November compared with the same month in 2005, and were 90.8 per cent up year to date at 4,107.
Land Rover, which has a gap in its model line-up until the new Freelander arrives in the US, saw its sales fall by 7.6 per cent to 4,229 last month.
The Solihull off-road specialist, which to some extent is shielded from the full impact of the strong pound by the fact that its cars are more fuel-efficient than US-built SUVs, was 6.4 per cent ahead at 41,760 on the year so far.
Overall, Ford group sales fell by 10 per cent to 182,259 last month, a performance that relegated it to fourth place behind General Motors (which gained six per cent), Toyota, which gained 16 per cent and Chrysler (up 4.7 per cent).
It was the second time this year that the fast-growing Toyota has overtaken Ford and analysts think that's a situation likely to prevail next year as the Blue Oval company continues to slash production as it tries to staunch losses totalling $7 billion so far this year.
Toyota, the world's number two carmaker by output, outsold Ford by more than 14,000 units in November.
"We're focused on returning our business to profitability in North America, full stop," Ford chief internal sales analyst George Pipas said, when asked about its drop in the rankings.
"I wouldn't want to comment on sales rankings. It's just not that important right now."
November marked the first time since 2002 that Ford slipped to fourth place in sales.
This mostly because of lower sales incentives, said Alex Rosten, industry analyst with Edmunds.com.
"They didn't launch their incentive program until mid-month. GM and Dodge were definitely more aggressive in incentive spending on trucks and SUVs."
Ford said its car sales were down three per cent per cent, mostly due to lower demand from fleet customers, while truck sales were off 13 per cent.
Ford has cut planned fourth-quarter production further by 15,000 units to 620,000 vehicles, down 22 per cent from a year ago. It expects first-quarter 2007 production to be down 14 per cent to 750,000.
Ford had said earlier production in the first half of 2007 would be eight per cent to 12 per cent lower.
GM, which is coming out of its slump earlier and faster than Ford, set its first-quarter production target nine per cent lower than a year ago at 1.4 million vehicles.
American carmakers have, in the words of GM analyst Paul Bellew, seen a "mini recession" this year as interest rates have risen and petrol prices have soared.
And with some gloomy economic indicators to contend with, the prospects for 2007 do not look that much brighter.