Franchised dealers enjoyed more than an 11-percent year-over-year lift in used-vehicle sales during September, according to CNW Research, which attributed the spike to a major dose of incentives and strong trade-in values.

The spike by franchised stores helped move the industry to an overall used sales total of 3.23 million units, up 4.6 percent year-over-year.

Specifically, franchised dealers moved 1.19 million units, a gain of 11.5 percent.

Meanwhile, independents moved 1.17 million used cars during September for a 5-percent hike, CNW noted.

Private-party sales were down 4 percent at 863,670 units.

In the first nine months of 2011, there were 30.16 million used vehicles sold, according to CNW. At this point in 2010, there were slightly less than 29 million used sales.