Carmakers yesterday pleaded with Chancellor Alistair Darling not clobber the motorist in next week's Budget.
He was urged by Paul Everitt, chief executive of the Society of Motor Manufacturers and Traders, to boost consumer confidence and avoid "disruptive or disproportionate" increases in vehicle and fuel tax.
His plea came as figures showed that new car registrations fell in February for the second month running.
Volumes dipped by 5.4 per cent to 69,610 units and were more than three per cent down at 231,707 over the first two months of the year, the SMMT said.
It means that UK dealers have sold nearly 7,500 fewer cars so far in 2008.
The fall in sales has come as no suprise to the SMMT, which has already trimmed its 2008 sales prediction by 2.5 per cent to 2.345 million as the economic storm clouds gather.
The organisation stuck to that estimate yesterday, even though it predicted that sales this month, which sees the introduction of the new 08 registration plates and is therefore a key month, will fail to match the "particularly buoyant" market seen in the same period last year.
In fact it expects sales this month to fall by 5.4 per cent to 425,000 year on year.
"New car registrations fell in February in line with market expectations," Mr Everitt said.
"It's important that the Chancellor uses next week's Budget to help boost consumer confidence and avoid disruptive or disproportionate changes to vehicle and fuel taxation."
Key West Midland carmakers Jaguar and Land Rover (which is still waiting to hear if Ford is to sell them to Tata Motors of India) saw their sales fall in February.
Jaguar was a hefty 60 per cent down with sales of just 173 cars last month - but its Castle Bromwich factory is working flat out to cope with a global order bank of nearly 15,000 for its new highly acclaimed XF midrange saloon car which went on sale on March 1.
February's figures also reflected the fact that Jaguar sold out of the S-Type - predecessor to XF - and the old version of the entry level X-Type - which has been given a facelift - at the end of last year.
It meant the company had only its two low-volume niche cars, XK and XJ on sale in January and February, a spokesman said.
Land Rover registrations in the UK fell by 30 per cent to 635 units in February, but comparisons with February '07 are skewed by the fact that then it had been catching up with backlog of registrations caused by a disruption to supplies of the TDV8 engines for Range Rover and Range Rover Sport at the end of 2006.
February 2007 was also the month that saw the launch of the successful new Freelander 2.
Land Rover, which is expanding rapidly outside its traditional UK and US markets, said yesterday that global sales rose by 15 per cent in February and by 17 per cent in January.
Chief executive Phil Popham, speaking at the Geneva Motor Show this week, said that the Solihull 4x4 specialist, which has had three years of record sales, was increasingly becoming a global brand.
"Our business prospects are promising this year dispite the threat of an economic downturn in North America," he said.
"We have already kicked off off with great start in January and February with sales substantially ahead of last year.
"A broad and increasingly international success helps to cushion us from the vagaries in any single market or region."
The depressed market affected Mini, which dipped by just over one per cent to 964 units last month while Toyota, which builds the Avensis and Auris at Burnaston in Derbyshire, fell by 24 per cent to 2,750.
Diesel sales continued their growth and were the best yet for the month of February.
Vauxhall enjoyed a good month in February 2008, with its Astra taking the top-selling model position from the Ford Focus. Vauxhall had four models in the bestsellers' top 10.
Among other companies that did well last month were BMW, Kia, Skoda and Volvo.
The SMMT said March sales this year were expected to fall decrease on March 2007, which was a particularly strong month.