With nebbishy-looking aqua-blue-and-white smart cars (Car2go), pink mustachioed vehicles (Lyft), and random cars picking people up at corners (UberX), it’s hard to miss all the new ride-share options in town these days. 

But there’s one option you may have missed. San Francisco–based Relay Rides is a network that operates like couch-surfing service Airbnb. When people aren’t using their cars they rent them out (say, $25 a day for a Corolla or $100 a day for an Infiniti G Sedan, with Relay Rides taking 25 percent), making good on the share-economy mantra that promotes both smart use of resources and the post recession frugality: Don’t let goods and services idle.

The company—which provides insurance, screens renters and cars (nothing older than 1990), and offers roadside maintenance—connects renters with owners on its website, emphasizing another big concept of collaborative consumption: While Car2go gives individuals access to a company resource, the Relay Rides business model gives individuals access to a market.