Evidence of an increasingly common trend, Dodge is offering a small incentive, $500 cash back, on the brand-new Avenger midsize sedan. The Avenger went on sale last month and is already selling well, despite the fact that national advertising hasn’t begun. Ford and Mazda recently offered similar incentives on new models that also looked to be popular. Usually, incentives are used to move unpopular or slow-selling models off the lots.