As manufacturers wheel and deal to move the iron off showroom floors, knowing which vehicles have generous manufacturer incentives and rebates greatly improves your chances of finding the best new-car deals.

Knowing manufacturers that are desperate to sell is also crucial.

Doing that kind of research can be an overwhelming undertaking, unless you know where to look. We called in the cavalry -- better known as the Internet in this day and age -- and found several Web sites, like CarsDirect.com and Cars.com, that offer information on the latest manufacturer incentives and rebates.

Edmunds.com takes the process one step further. As part of its True Market Value feature, Edmunds provides the average transaction price for vehicles sold in the U.S. and lists those with the greatest average discounted transaction prices in its "Deals of the Month."

And big deals they are. Take, for example, the 2009 Dodge Ram ST Crew Cab with an MSRP of $30,430 that has been selling for $20,452 -- almost 33 percent off sticker price.

According to Edmunds' senior analyst Jessica Caldwell, the manufacturers with the most deals tend to be Chevrolet, Dodge and Ford among domestic nameplates, and Nissan, Mitsubishi and Suzuki among the imports. "Volkswagen," she added, "does a lot of lease deals."

Some deals are available for only one specific payment option -- cash purchase, financed purchase or lease -- while others apply to two or all three.

Using those Web sites we've located a number of interesting deals. The discounted prices include all available incentives and rebates. Caldwell emphasizes that because Edmunds' transaction prices are based on national averages, consumers should use the data as a starting point to begin their research of regional prices.