A new report says auto affordability slipped in the third quarter of 2011. The purchase and financing of an average-priced new vehicle took 24.2 weeks of median family income in the third quarter of 2011, slightly more than the 24.0 weeks of median family income in the second quarter. Consumers on average spent $650 more (an increase of 2.6%) on new cars in the third quarter.

Why? One reason is because we’re making less due to the poor economy. MarketWatch has more.