DALLAS — The purchase and financing of an average-priced new vehicle took 23.2 weeks of median family income in the first quarter of 2011, unchanged from its fourth quarter 2010 level.

Consumers on average spent $400 more (an increase of two percent) on new cars in the first quarter. The average rates on car loans during the quarter increased to 4.7 percent, the highest average since the first quarter of 2009.

“The total cost of purchasing a new vehicle increased approximately $425 in the first quarter of 2011, as consumers opted for more expensive cars against a backdrop of rising rates,” said Dana Johnson, chief economist at Comerica Bank. “Looking ahead, affordability has the potential to erode as financing costs and consumer appetites for more expensive vehicles increase.”