The company says the service is available to Prime members at no extra cost and is limited to specific vehicle brands: Chevrolet, Buick, GMC, Cadillac and Volvo. Users can check their vehicle's entitlement on Amazon.com and then download the Amazon Key iOS app [Direct Link] to complete the setup.
"Since launching Amazon Key last November, we've certainly delivered everything from cameras to collectable coins in-house, and customers have also told us that they love features like keyless guest access and their front door from anywhere with the Amazon Key App, "said Peter Larsen, vice president of delivery technology for Amazon.
"In-car delivery gives customers the same security and allows them to take the Amazon experience with them, and with no additional hardware or devices, customers can start ordering in-car deliveries today."  Then customers buy as usual on Amazon.com or in the mobile apps from Amazon, select a suitable address and then dial in – Delivery at checkout The app gives customers a 4-hour window for delivery and requires that the car is parked within two blocks of the selected address.
Then, when the delivery arrives, Amazon says that it authorizes the delivery driver before unlocking the vehicle, and that "the driver is not given any special access or key". The app warns customers that the package is in their car and their vehicle is locked again.
In a section of the Amazon Key In-Car FAQ, Amazon explains how the platform uses an active Connected Car service plan (OnStar or Volvo On Call) to communicate and lock / unlock a vehicle:
Amazon Key enables in-car delivery by linking your Amazon Prime account to your Chevrolet, Buick, GMC, or Cadillac Owner Center account and an active connected vehicle connection plan. If you do not currently have an active connection plan, simply press the blue OnStar button in your vehicle to activate the service. Benefits vary by model, and most 2015 model cars and newer Chevrolet, Buick, GMC and Cadillac retail vehicles qualify for a standard connectivity plan at no extra cost.
Amazon says this process is safe with multiple layers of verification in the in-car delivery process. Each time a driver requests access to a vehicle, the company verifies that an authorized driver is in the specified location with the correct "through an encrypted authentication process" package. After this completes, Amazon unlocks the car, sends a notification to customers, and rescues the car after the package is secure.
There are a few limits to the parked car's location: Amazon states that in-car deliveries are only possible for one vehicle in an "open, street-accessible and publicly accessible area", ie no parking garages. However, customers can order "tens of millions" of items from Amazon and deliver them to a vehicle, the company said. Amazon Key In-Car starts today in 37 cities and surrounding areas in the United States.