If you’re in the market for a new GM or Chrysler product, it may be a good idea to join a credit union.

Credit union members across the country can now purchase 2008 and 2009 General Motors and Chrysler products at an additional discount — beyond any other rebates and incentives the two manufacturers are offering at the time. And don’t forget, credit unions normally offer lower interest rates on car loans than banks and finance companies.

Called Invest in America, the discounts started late last year as a pilot program for the credit unions and General Motors in four Midwestern states, and with Chrysler in 12 states. It was expanded last month to 7,800 credit unions nationwide.

The size of the discount depends on the vehicle. Chrysler rebates are $500 or $1,000, and apply to most Chrysler, Dodge and Jeep vehicles. GM is offering what it is calling the supplier price, which translates to a discount in the range of 4 percent to 5 percent on all Chevrolet, Pontiac, Buick, Cadillac, Saturn, Saab, Hummer and GMC vehicles except the Corvette and medium-duty trucks. For example a Chevy Malibu LTZ with an MSRP of $27,550 has a supplier price of $26,552. A Hummer H3 that normally retails for $34,135 has a supplier price of $32,157.

Dave Adams, of the Michigan Credit Union League, says the combined vehicle lending resources of credit unions in the U.S., “are on track to run as many as 1 million units through this program in 2009.”

GM’s program is scheduled to expire March 31 and Chrysler’s on June 30,  but Adams says he’s optimistic both companies will decide to continue the programs beyond those dates.

Although the members of all 7,800 credit unions qualify for the program, only about 1,000 credit unions were actively promoting the program with their membership as of Feb. 4, but Adams says more credit unions were coming on board every day.

At the end of the first quarter of 2008, credit union vehicle loan financing represented 14 percent of all new financing. By the fourth quarter of 2008, that figure jumped to 21 percent. Adams says Invest in America could mean a $10 billion loan surge for credit unions and a $5 billion boost combined for GM and Chrysler during calendar year 2009.

Invest in America is available to any current credit union member. Chrysler’s discounts are only available to members who finance through the credit union. GM’s discounts are available to any credit union member regardless of how they finance the sale. Of the estimated 25,000 program units sold through Jan. 31, about 90 percent have been credit union financed.

To find out more about Invest in America, contact a local credit union, a Chrysler or GM dealer, or visit LoveMyCreditUnion.org.