The automaker's experimental "roam delivery" service is built around the existing Volvo On Call telematics app, that lets users do things like remotely activating the heating or air conditioning in their parked vehicle.
In this case, however, they provide the company making the delivery with a one-time-use digital key to their car. When the delivery person reaches the vehicle, they use that key – via their mobile device – to unlock its doors. They then put the package inside, close the doors and lock them. The key ceases to exist after that, and the driver receives a notification of the times at which the vehicle was unlocked and locked.