Car loan rates fell for the third week in a row, further sweetening deals for those taking advantage of the government's new "cash for clunkers" program, which officially kicked off Monday.

The 48-month and 60-month new-car loans each fell 2 basis points, to 6.97 percent and 6.96 percent, respectively. Meanwhile, the average rate for a 36-month used-car loan held steady at 7.82 percent.

Already, 16,351 cars and light trucks had been sold under the CARS Act ("cash for clunkers"), says Eric Bolton, a spokesman for the National Highway Traffic Safety Administration. Those vehicles accounted for just over $68 million of the $1 billion authorized by Congress, he says.

That's good news for dealerships hard-hit by the prolonged slump in the U.S. new-car market. A spokesman for the National Automobile Dealers Association says that dealers have reported increased showroom traffic and a boost in sales since the program went into effect.

To find updated auto rates in your area, visit Bankrate's auto rate table.

-- Claes Bell