The Unted States House of Representatives has approved extra funding to extend a car rebate system.
Under the scheme, people who trade in their old cars for more efficient models receive cash payments.
The programme was backed by $US1 billion of stimulus funds, but has proved so popular that more cash is needed.
The House has approved an extra $US2 billion and the Senate is expected to vote on the matter next week.
Officials previously projected that $US1 billion would be enough to fund 250,000 transactions.
They planned for the scheme to operate until 1 November or until the money ran out.
But the BBC reports sales volumes have been unexpectedly high and funding is drying up more quickly than had been predicted.