Amazon added a new delivery location to the ever-growing number of spots it can leave your packages: inside your car. The company announced an expansion of its Amazon Key in-home delivery service that now lets Prime members get packages deposited in their cars at no extra cost. The service is available today in 37 cities across the country for Prime members with eligible vehicles and active subscriptions to connected car services.

The in-car delivery service only requires the Amazon Key app and a car of recent vintage. Before placing an order on Amazon, Prime members can choose the "in-car" delivery option at checkout. On the day of delivery, customers can check if their car is parked in-range of the delivery location in the Amazon Key app.

Before couriers gain access to the customer's car, Amazon uses an "encrypted authentication process" to make sure the right courier is present in the right location with the right package. After authorization, the car is unlocked so the courier can deliver the package inside. As with most Amazon delivery services, customers receive alerts when a package is about to be delivered and after the package has been left in their car.

Remote unlock

No special, one-time access codes are required for in-car delivery, as the car is remotely unlocked at the time of delivery and then immediately locked afterward. Amazon does this through the user's connected-car service that's paired with the Amazon Key app. Currently, compatible 2015 or newer Chevrolet, Buick, GMC, and Cadillac vehicles with active OnStar accounts can receive in-car deliveries, as can 2015 or newer Volvo vehicles with active Volvo On Call accounts.

Services like OnStar and On Call have had the power to remotely unlock cars for years, which comes in handy when drivers panic after realizing they've locked themselves out of their vehicles. Now, a feature like that can be used to make a customer's day more convenient in addition to helping out when a situation turns dire. Those who spend a lot of time at work but aren't allowed to get personal mail in their office could use their cars as a secure delivery receptacle.

But anything associated with Amazon Key will raise eyebrows if the word "secure" is uttered. Launched at the end of the last year, Amazon Key began as an in-home delivery service that allows Amazon couriers to drop off packages inside your home using a special security camera and smart lock hardware. Many customers were skeptical about allowing a stranger into their home, and some will likely feel the same way about giving a stranger access to their vehicles.

However, users may be more open to trying in-car delivery than the alternative. Users may have more peace of mind knowing that OnStar, On Call, and other services can restrict unlocking to only one part of the car (like the trunk), limiting the access that a courier has. There's also precedent for such a service: in 2015, Audi teamed up with Amazon and DHL to offer in-car deliveries in Munich, Germany to a select number of Audi drivers. The success of that program likely encouraged Amazon to give a similar service a shot in the states.

In general, there appears to be less of a stigma around giving a delivery person access to your car as opposed to your home. That mental and societal distinction between home and car has given companies leeway to experiment with convenience programs that require remote access to vehicles. In 2016, Volvo announced a trial concierge service that allows Bay Area S90 and XC90 owners to get their cars refueled, serviced, or valeted through a smartphone app. Using a one-time access code, car owners can give authorized personnel access to their vehicles for a limited time so the customers can go about their day while someone else fills up the gas tank, gets the car serviced, and more.

Amazon is determined to give Prime customers as many perks as possible, and the company keeps trying new ways of securely dropping off packages. In-car delivery is just another way for Amazon to make its overall delivery system faster and more convenient. With more delivery options comes more customers willing to shop on Amazon, knowing that they can get their package quickly and securely no matter where they are.