WASHINGTON (AP) — The government says it's paid dealers compensation for 70 percent of the cars sold under the Cash for Clunkers program.

Transportation Secretary Ray LaHood told the National Automobile Dealers Association on Wednesday that 478,000 of the nearly 700,000 car vouchers have been paid, or about $2.4 billion.

Under the program, car buyers could qualify for incentives of up to $4,500 to trade in their old gas guzzler for a new vehicle.

Dealers had complained about delays in getting reimbursed. LaHood said he was grateful to dealers for "hanging in there and being patient."

LaHood told dealers the government was "stunned" by the initial success of the program when 250,000 vehicles were sold in the first four days.