Mr Truss says the Federal Government's last minute amendments will exempt certain Mercedes, Jaguars, Audis and BMWs from its luxury car tax surcharge.

But he says the tax increase will still hit the price of Landcruisers and Taragos for families, farm workers, rural doctors and vets.

The increase in the Luxury Car Tax passed through Parliament today in what he says is a "confused form that will hit country communities hard".

"I find it astonishing that city motorists driving a Jaguar can get a tax concession but a shearer in a Toyota Landcruiser cannot," Mr Truss said.

"Large families needing a Tarago people mover will cop a new tax but someone driving a turbo-charged Saab will not.

"Country doctors called out to visit patients along dusty or slippery dirt roads need a safe and reliable four-wheel drive.

"Vets tending sick animals across kilometres of outback paddocks need a safe 4WD workhorse.

"Many of these vehicles will now be subject to the luxury tax surcharge while city executives will be able to drive a Mercedes or BWM without paying the tax."

Mr Truss said the Coalition's proposed amendments would have retained the LCT for vehicles priced between $57,180 and $90,000 at 25pc, and increased the tax to 33pc for vehicles purchased above this amount.

This would have protected the ordinary Australians who purchase cars such as Toyota Landcruisers and Taragos, Holden Commodores and Mitsubishi Pajeros which are priced above $57,180 but generally less than $90,000.

The top-selling 'luxury car' in Australia is not actually a Rolls Royce (17 sold across Australia last year) or a Porsche 911 (522 sold in 2007) but the Landcruiser, of which 6,000 were sold.

Many were sold in rural areas and are used in the course of business.