Got a car you don’t use? Or even one you do, but can spare for a few hours to a complete stranger? You could be making some cash using new peer-to-peer car sharing services that set up car owners with people in need of a ride.

To wit: CNNMoney profiles one man who happens to have a BMW 5-series that he doesn’t need to use all that often, so he rents it out for $15 an hour or $75 per day through a national company called RelayRides.

“With monthly payments and insurance, I was in the black last month,” he said. “Basically, I have the car for free.”

There’s another smaller competitor company, Getaround which is in a few certain markets. The companies each provide up to $1 million worth of liability insurance coverage on cars while they’re being rented.

Owners have the right to refuse rental requests, of course, even if they just don’t like the sound of someone. Or perhaps someone leaving trash in your car won’t make you likely to rent to them again.

There are problems, as in one recent case where a RelayRides user’s car was involved in a fatal wreck. In that example it’s tricky to figure out who pays the damages, so insurance industry insiders warn car owners to check with their providers before using a peer-to-peer service.

“We advise consumers who participate in peer-to-peer ride sharing to read their insurance policies carefully and talk to their insurance agent to make sure they know exactly what is covered,” said Loretta Worters, vice president of the Insurance Information Institute.

Rent your car for cashn [CNNMoney]

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