Update: On April 15th, FlightCar announced that it had raised $5.5 million from a group of investors that included General Catalyst, Airbnb founder Brian Chesky, and "American Idol" host Ryan Seacrest.

Co-founder Shri Ganeshram tells me he is moving back to Cambridge this week, where the plans to begin recruiting additional employees; he hasn't yet figured out where FlightCar will be based. "We're looking to hire designers and software developers at the moment," he says. The startup participated in the Y Combinator accelerator program in Silicon Valley earlier this year.

By Scott Kirsner, Globe Columnist

What if you could drive to the airport, hand your keys to a valet, get free parking for as long as you wanted, and have your car washed and cleaned. Oh, and you'd get a free gas card when you returned to pick it up?

A California start-up called FlightCar is testing the concept at San Francisco International Airport. There's just one catch: while they have your car, they rent it out to other travelers. It's a fascinating new twist on the car-sharing business model, which includes big companies like Cambridge-based ZipCar (now part of Avis) and smaller start-ups like RelayRides (founded in Cambridge by a Harvard Business School alum).