Four of the five top-selling new cars sold under the US government’s CARS/’cash for clunkers’ rebate scheme were made by Japanese automakers, albeit mostly in North America, media reports citing transportation department data said.

Ford’s Michigan-made Focus ranked top followed by Toyota‘s Corolla (California and Ontario) and Honda’s Civic (Ohio and Ontario) while Toyota’s Prius (Japan) and Camry (Kentucky) took fourth and fifth places respectively, according to CNN and other media.

‘Cash for clunkers’ introduced in the last week of July boosted sales of new cars made by Japanese-owned brands which specialise in fuel-efficient models.

Reports said many trade-ins were old Detroit gas guzzlers such as the Ford Explorer SUV and Dodge Ram pickup truck. TV news bulletins showed many old full-size passenger vans were also being turned in. Scheme rules dictate they all be destroyed though engines can be recycled.

Subject to complex rules, buyers can get up to US$4,500 off the price of a new vehicle with higher fuel economy and many automakers are adding top-up incentives of their own.

Honda’s Fit (Jazz) compact was ninth among the top 10 cars purchased under the CARS programme, as Japanese automakers accounted for half the top 10 models.

Senate majority leader Harry Reid said on Tuesday that he intended to get a bill passed within a week, to add $2bn more to the programme’s original $1bn allocation of federal funds exhausted in about a week.

Chrysler also quickly ended a related incentive that gave some buyers up to $9,000 discount, claiming that dealers were running short of qualifying vehicle stocks.