If you're heading to the dealership to turn in your leased car and you haven't checked to see what it's worth, you could be walking away from thousands of dollars in cash. Because of rising used-car values and a variety of other factors, some happy consumers are pocketing checks or reducing the payment on their next cars.

"That money, that equity, is yours. Period," says Oren Weintraub, president of Authority Auto, a concierge car-buying service.

This may surprise many consumers. Sergio Stiberman, CEO of LeaseTrader.com, points out that until recently, "the words 'equity' and 'leasing' never went together."

What's changed? To answer that, here's a quick review of the way car leasing works.

Leasing companies predict what cars will be worth at the end of the lease term. This is the residual value that the lease calculation is based on. It is also what you can buy the car for at the end of the lease.

Edmunds visitors save an average of $2879 off their new car. How much can you save?

Leasing companies are pretty good at predicting that residual value. But because of fluctuations in the marketplace, some cars might be worth more than the residual value. Since you have the right to buy the car at the end of the lease term, you can profit from the lease company's inaccurate lower estimate. If, on the other hand, the car is worth less than the residual amount, you can turn the car in without incurring an extra expense.

Two factors — low new-car inventories and tight credit — have aligned to raise used-car prices. This has put consumers in charge when it comes to leasing.

Dianne Whitmire, fleet manager for Carson Toyota in Carson, California, says she uses the equity in returning lease cars to help her customers in a variety of ways. But it's a well-kept secret, she says.

She had one customer with two cars — one was a leased car with equity and one a purchased car that was "upside down," meaning that the loan balance was greater than the car was worth. "In that case, one washes the other" to pay off the loan, she explains.

Brandon Park, general sales manager at Nissan of Downtown L.A., says that people who have leased through his dealership will usually return the car to it, even though they are free to go to any other dealership. Park's used-car manager appraises the returning vehicle to determine its current market value and lets the consumer know if it has any equity. Many customers use the equity as a down payment on their next car (either leased or purchased) and consequently find the monthly payments for that car are lower than they were paying for the leased car they just returned.

Not all returning leased cars have equity, says LeaseTrader CEO Stiberman, whose company helps consumers transfer car leases. When current high used-car prices settle down, equity-packed lease cars may be less common. Still, anomalies can occur in the marketplace at any time, so smart consumers should keep an eye on the market value of their leased cars.

Stiberman says that on his Web site, a consumer can post a leased car so dealers can arrange to buy the vehicle and give him a check for the equity. And the consumer doesn't have to wait until the lease is over, he says. He can sell his leased car any time during the contract.

As an example of what is at stake when a leased car has equity, Weintraub gives the example of a client who had a Mercedes-Benz GL450 that was near the end of its lease. The car had minor body damage, and the client was going to pay $1,800 in excess mileages fees, as well as a $400 disposition fee, charged at the end of some leases. By arranging to sell the car to a dealer, the client incurred none of those expenses and actually pocketed $3,200 in equity. The client was "in shock" at the windfall, Weintraub says.

The used-car superstore Carmax is another place where consumers can go to get equity from their vehicle. "In most cases," according to the site's FAQ, "you can sell your leased car in almost the same way as any other financed car. We'll appraise the car or truck, then contact the leasing company for a payoff quote and process any equity you might have."

Carmax notes that some leasing companies don't allow such an arrangement. Check your lease agreement for any such language.

How To Know If You Have Equity

Experts say it's important to watch the value of your leased car, particularly as it approaches the end of the lease term. Stiberman suggested using Edmunds' Used Car Appraisal tool to get the trade-in and private-party values of the car. Next, in your lease contract, find the residual value. Subtract the residual value from the current market value and this is the approximate equity you may have, subject to negotiation with the dealer. Knowing the Edmunds True Market Value (TMV®) current market value of your leased car, and even providing printouts of the price to the dealer, will strengthen your negotiating position.

If your car is still a year or more away from the end of the lease term and you want to check for current equity, call your leasing company and ask for a buyout price. Subtract the buyout price from the current market value of the car to see if you have equity.

3 Ways To Turn Equity Into Cash

If you have equity in your leased car, here's how to turn it into cash. Keep in mind, though, that this is advanced car financing and not, as Weintraub puts it, "Car Buying 101."

1. Sell your leased car and get a check. You can take your car to any dealer, not just the one where you arranged the lease, and let the dealer buy the car at the trade-in price, which you can find in the Edmunds TMV pricing. The dealer will pay the leasing company what you owe and give you a check for the equity. However, Whitmire cautions, don't expect the money immediately. The dealership will mail you a check once it gets a clear title, assuring that your car doesn't have a passel of parking tickets attached to it. You also should make this a written agreement, and include in it the amount due to you, Weintraub says.

2. Sell your leased car to a neighbor, friend or family member. This method requires a bit of trust, so it helps to sell your car to someone you know. However, this will work with any buyer you find, and it will get you the private-party price for the car, which is higher than the trade-in price dealers pay.

Here's what you do: After finding a buyer, get him to mail a check for the buyout amount to the leasing company. Once you receive the title (the leasing company will only send it to the person leasing the car), sign it to release your interest in the vehicle and give the title to the buyer. The buyer can then register the car and pay sales tax at that time. Be careful here, however. If the buyer waits longer than 10 days, the state might try to charge you both sales tax, which would wipe out your profit.

A way to prevent this, according to the Auto Club of Southern California, is to pay the sales tax and DMV fees as soon as possible and then return to conclude the deal with the title in hand. This transaction is called a "lease buyout transfer." Contact your state's DMV for more details.

3. Make a down payment on your next car. In this scenario, the equity in your current car becomes a cash down payment for the new one. Once you know you have equity, you can take your car to any dealer to begin a new lease or sales contract. Negotiate just as aggressively as you normally would. Not all dealers will offer you the same amount for your leased-car buyout, so you might have to shop around for the best offer. It should be close to the Edmunds.com trade-in price. Weintraub says you might get more money if you are going "brand to brand," meaning selling a Toyota to a Toyota dealership, although any dealership can handle the transaction.

It's still important to make sure all the numbers add up, however. Agree on the exact amount of equity you will receive and look for that amount in the down payment box on the contract. Alternately, you can also use the equity to pay the "drive-off fees" to begin a new lease, rather than pay that money out of pocket.

A Reason To Consider Leasing?

In the past, some experts criticized leasing as being too expensive and restrictive. But with high used-car values and a leasing market that has gone from dead to dynamic in the last couple years, it might be time for a second look.