BURLINGAME, Calif. — Three teenagers are facing a lawsuit from the city of San Francisco alleging that their startup company that allows people to rent cars out to other airport travelers is not following airport regulations.

The lawsuit was filed in San Francisco Superior Court on May 31.

FlightCar launched in February and rents out people's cars while they are traveling. The company gives car owners a share of the proceeds, free airport parking and a car wash in exchange.

The city says the company needs to follow airport rules for rental car companies serving the airport, including 10 percent of gross profits to the airport and paying a $20 per rental transaction.

Other "sharing economy" companies such as Sidecar, Lyft, and Airbnb are facing similar conflicts around the country.