There are some people who couldn't imagine a time when they'd let someone else drive their car - let alone take it away for a spin on their own. However, there are around 5,000 people in the UK who are prepared to hand over their keys - in much the same way as Airbnb users hand over theirs - and they're making a fortune in the process.
Chief executive of easyCar Club, Richard Laughton, says this is simply the sharing economy coming to the world of cars - making everyone better off in the process.
Renters can get a bargain, and they can track down someone lending out their car within easy reach of their house, so they don't have to slog all the way to a car rental place.
They have some protections in place, because the cars need to be owned outright, less than 15 years old, with fewer than 100,000 miles on the clock. You also have your insurance and breakdown cover arranged for the duration.
Would you rent out yours?
Owners can make decent money. Francesca Knott is a 29-year-old management consultant from Dulwich, and she has been letting people rent her car since 2013. She says: "When I bought the car, I was working full time, and the car spent a huge amount of its time sitting outside the house doing nothing. It felt like a wasted asset, so I decided to try renting it out."
She has rented it for two of the past three years, and now gets around two requests a week, which she agrees to a couple of times a month. She has made £2,000 in two years, which has covered her running costs, and she says: "I haven't actively promoted it, or accepted all the requests, so I could probably make twice this amount."
There are protections in place for owners too. There's a licence check - to make sure drivers don't have too many points on their licence, or too many insurance claims. Those who want to rent also take place in a video call, to confirm their identity. The company arranges insurance for any periods that the car is rented out, and takes a deposit from the driver to cover any excess.
It's not going to work for everyone. Francesca has had a couple of incidents when a driver went through the congestion zone without paying, and when one got a speeding ticket. She says: "easyCar make it easy to deal with, and you would never be liable to pay these things, but these things do happen."
Laughton agrees: "It's not going to suit everyone, and we know it's better for people who don't have a huge emotional attachment to their car, but if it does suit you, it could be a great way to offset the cost of owning a car."