Chicago Average auto debt per auto loan borrower nationally rose 0.13 percent in the fourth quarter to $12,738, according to a report from TransUnion.com. The largest state average was in Nevada at $16,133, followed by the District of Columbia at $15,818. The lowest average auto debt was in Michigan at $10,454.

"It is not surprising that the greatest levels of average auto loan debt are found in areas with some of the biggest population growth rates in the country, or where decentralized metropolitan areas make car ownership more of a necessity than a convenience," said Ezra Becker, a principal consultant in TransUnion's financial services group. "It is in these markets that demand is higher and thus prices are greater. It also may be that auto loans in these regions are relatively younger and hence have higher balances. Demand is lower and loans are more seasoned in states like Michigan, Nebraska, Maine and Ohio, thus balances are generally lower as the average auto loan gets closer to its payoff date."

The steepest increases in average auto debt -- correlating perhaps to greatest demand --occurred in Oregon (3.55 percent growth), the District of Columbia (3.34 percent) and New Jersey (1.91 percent). Montana experienced the sharpest drop in average auto debt (-3.7 percent) followed by Maryland (-1.5 percent).

Auto loan delinquency (the percentage of auto loan borrowers 60 or more days past due) was highest in Louisiana at 1.44 percent, followed closely by Mississippi at 1.43 percent. The lowest auto loan delinquency rates were found in Alaska (0.16 percent), North Dakota (0.40 percent) and Wyoming (0.47 percent).

"From a risk perspective, auto loan delinquency seems to mirror the continued economic downturn that has plagued southeastern states like Louisiana and Mississippi in the long wake of Hurricane Katrina, and has been indirectly exacerbated by the continuing mortgage crisis," Becker added.