ZipCar-style car sharing services, where you pay to rent a vehicle by the hour, are already a thing across much of the US. But Toyota is looking into the idea of individuals being able to lease out their own cars on an hourly basis to make some extra cash. The manufacturer has teamed up with a startup called Getaround to begin a limited trial of the proposition at the start of next year. In order to make that work, however, the company has had to work out an easy way of enabling third parties to access your ride. That's where the Smart Key Box, or SKB, comes in.