From Vermont to California, exhausted but appreciative car dealers watched their lots grow empty as crowds rushed to trade in gas guzzlers during the final weekend of the popular cash for clunkers program.

The hectic pace of the $3 billion rebate program accelerated in the final weekend, after the government announced the program would end today at 5 p.m. PDT, two weeks earlier than expected.

Adding to the urgency, some dealers had said they would stop cash for clunkers sales even earlier to make sure the government reimbursed them for the rebates – or because they didn’t have enough eligible cars left.

In the final hours, customers streamed in. Though short of some new models, many dealers were still selling as many cars as they could before tonight’s deadline.

As of early Friday, nearly half a million cars had been sold through the program.

But many dealers worried about not being reimbursed. As of Friday, dealers had been reimbursed for just a small fraction of the billions in sales.