SANTA MONICA, Calif. — There are a number of current new car tax credits expiring at the end of December and online automotive information resource Edmunds.com says would-be car buyers should consider this timing in their purchase decisions.

“Credits are expiring once and for all on a huge swath of new cars, unless there’s a successful lame-duck effort in Congress to extend them,” noted Carroll Lachnit of Edmunds.com.

“Hybrid, diesel and compressed natural gas (CNG) vehicles purchased after Dec. 31, 2010, will no longer be eligible,” said Lachnit. “But the tax credits for plug-in hybrids like the Chevy Volt and electric vehicles like the Nissan Leaf are likely to remain in effect for several years.”

However, Edmunds.com says tax credits aren’t the only factor to consider. Ron Montoya of Edmunds.com adds that dealers may push up prices for in-demand cars, and that can negate much of the tax savings if buyers aren’t careful. "For some models, buyers will realize better savings if they wait until ‘hot’ models cool off,” he said.

Montoya points to the Honda Civic GX and Hyundai Sonata Hybrid as two examples.

View a full list of vehicles eligible for the tax credit here.