Still, lower fuel costs have led to an increase in the sale of light trucks among domestic manufacturers with June sales improving 2% over April's figures, according to NAFCU. Meanwhile, vehicle sales are expected to pick up in the second half of the year amid inventory shortages and more incentives.

Brian Turner, director of advisory services at Southwest Corporate Investment Services, a wholly owned CUSO of Southwest Bridge Corporate Federal Credit Union, offered his take. He said a return of manufacturer's incentives were still not good enough to spark sales of domestic vehicles in June.

Total sales fell to an annualized pace of 11.5 million units, down from May's 11.8 million level.

Turner said it was the fourth consecutive month-to-month decline in motor vehicle sales, which is a principal component of retail sales.

Unemployment, volatile home prices and an unsteady stock market are the culprits behind the hesitancy to buy.

"Instead of opening their wallets, [consumers] have virtually chosen to defer their spending on big ticket items such as cars, home and appliance electing to reduce their debt load," Turner said. "This has certainly contributed to weak loan demand, especially in the credit union industry."