A San Francisco-based company is putting yet another spin on the Washington area’s sharing economy, giving travelers flying out of Dulles International Airport free parking and a car wash in exchange for permission to rent their cars to other drivers.

FlightCar launches Wednesday at Dulles and two other U.S. airports. Participating travelers can drop off their cars at a designated lot near Dulles. In exchange for letting FlightCar offer a vehicle for rent, the travelers receive free parking, a Town Car ride to the airport, a car wash and per-mile payment if the vehicle is rented — to a pre-screened driver — while they’re away.

“Everyone goes to the airport, everyone has trouble parking, so it just make sense,” said Kevin Petrovic, president and co-founder of FlightCar.

The new venture is similar to RelayRides, which has been operating in the Washington area since 2012. The companies have different payment structures, but both enable people to make money from the rental of their vehicles to others.

The businesses are targeting a lucrative U.S. rental car market, which in 2013 brought in $23.6 billion in revenue, according to the Automotive News’ 2014 Fact Book.

FlightCar’s entrance into the Washington area is another sign that the region’s affluent, tech-savvy residents and its growing population of millennials make an attractive target for companies seeking a piece of the sharing economy, in which people enter into agreements to share resources .

“It’s a good test market,” said Jim Wolfe, entrepreneur in residence at the School of Management at George Mason University. “There’s a critical mass of young people who don’t come with preconceived notions of how the world works.”

Brooks C. Holtom, an associate professor of management at Georgetown University’s McDonough School of Business, agreed.

“San Francisco is an early adopter on technology as is Boston, and D.C. is pretty close to that mix,” Holtom said. “People here are early adopters who like to be on the cutting edge.”

Wolfe said FlightCar and similar companies also demonstrate how the concept of ownership has continued to evolve.

Earlier ventures — including Car2Go, Zipcar and even Capital Bikeshare — have demonstrated the willingness of people to borrow rather than own. FlightCar and RelayRides go a step further, giving people a chance to lend something they own in exchange for payment.

Wolfe said for some people, it’s simply a way to maximize the value of an asset.

But as with many such start-ups, there are regulatory questions because such companies may not fit under existing laws and regulations.

FlightCar is not based at Dulles, but at a nearby location, so it’s not clear whether its operations run afoul of regulations that govern car rentals at the airport. Petrovic said the company is in discussions with Dulles about permits.

Airport officials confirmed that they had been contacted by FlightCar.

“As with any service offered at our airports, including FlightCar, a permit is needed to operate at Dulles International and Reagan National airports,” Chris Paolino, a spokesman for the Metropolitan Washington Airports Authority, said in an e-mail. “We select rental car operators at Dulles through an open, competitive procurement process, most recently completed last year. FlightCar did not participate in that process, nor have they been granted a separate permit for operation. Without a permit, they would be in violation of Airports Authority regulations and would be subject to legal action.”

Other ventures have run into similar roadblocks, for instance, increasingly popular ride-sharing services that use smartphone applications to connect riders and drivers

In 2012, Uber ran into trouble with D.C. officials who cited drivers for providing taxi-limousine service without proper licensing. This summer, the Virginia Department of Motor Vehicles issued cease-and-desist orders to UberX and Lyft — whose participating drivers use their own cars to give people rides — until the companies agreed to get temporary operating permits.

Last month, the D.C. Council approved legislation that allows Uber, Lyft, Sidecar and other app-based ride-sharing services to operate in the District without having to observe many of the rules that govern cabdrivers. Such arrangements have not been established in Virginia and Maryland, although officials expect the two states to address the issue in next year’s legislative sessions.

Insurance coverage also has been an issue for ride-share services. FlightCar provides primary liability insurance up to $1 million — in addition to other types of coverage — when the vehicle is in its possession, Petrovic said. Relay Rides offers primary liability coverage up to $1 million during the time of a rental.

FlightCar service already operates in San Francisco, Los Angeles, Boston and Seattle, and is adding airport sites in Philadelphia and at Dallas Love Field, in addition to Dulles.

Relay Rides brokers rentals at more than 300 airports, including Dulles and National, and in more than 2,000 cities. Although it makes recommendations on rental rates, it leaves it to owners to set the price and arrange to meet the renter. The company takes a 25 percent cut of the rental fee.

Both companies screen the driving records of potential renters.

Still, while hopping into a car driven by a stranger, a la UberX, might be gaining broad acceptance, lending your vehicle to a complete stranger may be a tough sell, said Georgetown’s Holtom, whose travels often take him through Dulles.

It would be nice to get free parking and a car wash, he said, but his kids, who have grown up steeped in technology, may be more willing to take FlightCar up on the offer.