SANTA MONICA, Calif. -

Used-car sales for September are likely to fall double-digits from August, but even with this large sequential downturn, the used market is still projected to beat year-ago sales by more than 4 percent, according to TrueCar.

Specifically, the firm believes September’s used sales total will come in at 3.23 million units once the month wraps up Friday. This would be a 15.4-percent slide from August, but a 4.5-percent lift from September 2010.

Over on the new-car side of the market, things appear to be quite rosy, despite financial ups-and-downs and fear of a recession, TrueCar said.

Though sales are expected to drop 1.6 percent month-over-month (unadjusted), September’s projected new-car sales total is a 10.1-percent year-over-year hike and would result in the strongest seasonally adjusted annualized rate in five months, TrueCar reported.

The company is projecting 1.05 million new-vehicle sales for the month, with the resulting SAAR being 13.1 million. That compares to a SAAR of 12.1 million a month ago and 11.7 million a year ago.

“New-vehicle sales are doing particularly well, even with worries of a recession and another wild month for the financial markets in September,” stated Jesse Toprak, TrueCar’s vice president of industry trends and insights.

“If the current trends hold, we expect 2011 total new light vehicle sales to be 12.75 million units — up 10 percent from 2010,” he added.

Among the seven largest OEMs, predicted to make the most headway from a year ago is Hyundai/Kia, whose forecasted sales of 95,424 units represent a 24.5-percent improvement.

Also forecasted to show more than 20-percent gains are Chrysler (up 20.5 percent) with expected sales of 120,579 units, and General Motors (up 21.2 percent). TrueCar believes GM will move 209,554 units.

Nissan — expected to be up 19.3 percent at 88,522 sales for the month — wasn’t far behind.

Ford is projected to see its sales jump 8.5 percent and come in at 174,036 units.

Honda and Toyota are the only two of the top seven OEMs forecasted to dip from September. Honda is expected to be down 2.6 percent at 94,857 sales with Toyota off 11.6 percent at 130,057 sales.

That said, these two were the only ones whose sales will likely climb from August, with Honda up 15.2 percent and Toyota seeing a 0.4-percent rise. The other five OEMs are believed to have dipped from last month.

Honda and Toyota are also putting more money toward incentives, TrueCar indicated. In fact, their incentive spending is hitting record levels.

The forecast for Honda’s September incentive spending is $2,370 per vehicle, up 6.4 percent from August and up 7.5 percent year-over-year. Toyota is at $2,472 per vehicle, up 2.2 percent month-over-month and 16.5 percent from September 2010.

“Now that Honda and Toyota have increased levels of inventory, they are spending money at record levels to move cars,” explained Kristen Andersson, automotive analyst at TrueCar.

Overall, the industry’s incentive spending for September is forecasted at $2,716, a 0.9-percent year-over-year drop and a 3.8-percent sequential hike.

TrueCar also delved into market share for the seven OEMs. Leading the pack for September is GM, with a forecasted share at 19.9 percent, followed by Ford at 16.6 percent. And Toyota appears to be back in the No. 3 spot with a projected market share of 12.4 percent.

Last month, Chrysler edged out Toyota for third-place, as it took a 12.2-percent share compared to Toyota’s 12.1 percent. For September, Chrysler is predicted to claim fourth-place with an 11.5-percent share.

Rounding out the list were Hyundai/Kia (9.1 percent), Honda (9 percent) and Nissan (8.4 percent).

TrueCar provided the following data to better illustrate its findings: