Timing a purchase is all about balancing price and selection, and buying a car is no exception. With the auto industry on the upswing and scaling back cash incentives the time to buy may be now.

The average incentive fell to $2,654 in April from $2,806 in March, a 5.4% drop and a 13.2% decrease from April 2009, according to automotive data aggregator Edmunds.com.

What s more, thanks to the cash for clunkers program and increased sales, inventory could be sparse going into summer, says Jeff Schuster, the executive director of forecasting for J.D. Power & Associates. We don t have a glut right now, he says. That s a situation auto makers haven t been in for awhile.

After a period when the Big Three -- General Motors, Ford and Chrysler cut back on incentives, they rebounded somewhat this spring as Toyota used sales to apologize for its widespread recalls. That forced competitors to follow suit. No one wants to do it, but as soon as one does they all have to, says David Whiston, an analyst who covers the industry for Morningstar. Otherwise, only the person who first [cut prices] benefits.

What deals are left? Here is a guide for prospective buyers:

Cash back

Cash back is one of the incentives auto makers like the least, says Jessica Caldwell, a senior analyst at Edmunds.com. Unlike financing deals, it pushes down vehicle values. But it s also necessary to attract buyers who can t get or don t want financing, or who are owe more on a trade-in than the vehicle is currently worth. Pushed by Toyota s increased spending, average Honda incentives reached a record high of $1,787 in April. Even the popular Accord, for example, carries $1,200 in dealer cash. Chrysler is also offering fairly high cash-back rates, at an average $3,374 per vehicle. Check incentives listings at Edmunds.com and Kelley Blue Book to make sure you re getting the maximum.

Low-rate financing

Cheap financing made a comeback in March, with many auto makers offering 0% for 60 months on some models. We re starting to see these more as the credit market loosens up, Schuster says. Even Porsche is offering 1.9% for 60 months on four of its models when you buy before June 30. But the marketing may be deceptive for many consumers. Depending on the brand, buyers still need an excellent credit score of at least 700 on the 300- to 850-point scale to snag those low rates, says Jack Nerad, the executive editorial director for Kelley Blue Book, an auto pricing information site.

Lease deals

Looser financing has also dropped lease prices. You re talking $200 a month for some pretty doggone good vehicles, Nerad says. Toyota brand Lexus is offering lease promotions for the first time through a new Unprecedented Access program for loyal buyers. But again, the enticing lease rates are available only for buyers with excellent credit.

Combo offers

Financing and cash back is usually an either-or decision, but auto makers occasionally roll out combo offers, Caldwell says. Chrysler is currently offering several through June 1, including 0% for up to 60 months, plus $1,000 cash back on a 2010 Jeep Grand Cherokee. (Buyers can also opt for 1.9% for 72 months and $1,000 cash back.) If you don t qualify for the best rate on financing, crunch the numbers to see if you might get a better deal with a bigger cash-back-only offer on another model.