Amazon now delivers to the trunk of your car

CNN Money —  Amazon turned the trunk of my car into a mailbox.

The tech giant has launched a new service in 37 US cities (including the Salt Lake City area) that delivers packages to the trunks of cars for free. The catch? You need to be a Prime member.

I spent a week testing the service and became convinced this is the future of urban deliveries — for those with the right cars.

For it to work, I needed an eligible vehicle — nearly all Chevrolet, Buick, GMC, Cadillac and Volvos with a model year of 2015 or newer are compatible. GM owners must have an active OnStar account, and Volvo owners need an active On Call account. These systems provide remote access to vehicles, which makes Key In-Car possible.

I borrowed a recent model Volvo from Amazon — my Hyundai Elantra GT didn’t qualify — and downloaded the required Amazon Key app. In November, the company launched Amazon Key, which uses a camera and smart lock so Prime members can have deliveries brought into their home.

Its latest iteration, Amazon Key In-Car, relies on the vehicle’s internet connection to remotely open the trunk so packages can be delivered. Amazon’s delivery people receive one-time access to open the trunk. An alert is sent to customers when the process is completed.

Last week, I purchased a pack of D batteries on Amazon.com for $10.65. At checkout, a new option appeared for “in-car delivery.” I was given a four-hour delivery window — between 11 a.m – 3 p.m. ET.

I was told the car needed to be parked within a couple blocks of the delivery address in a publicly available spot. I chose my home address, and parked around the corner from my front door on a crowded block. After a customer adds their car’s color, make and model into the app, a delivery person can find it with the aid of GPS.

Related: Amazon Key will let delivery people inside your home

During my test, I received a push notification from Amazon: “Arriving soon: Your package will be delivered to your Volvo.” Under normal circumstances, an alert like this would give me anxiety.

“Porch pirates,” people who walk off with deliveries left outside homes, are a problem in my Washington, DC neighborhood. In a local Facebook group, my frustrated neighbors regularly post videos of their packages being stolen — their doorbell cameras don’t seem to deter theft. Rather than risk losing a package, my wife and I generally get packages delivered to family members who live elsewhere.

For city residents like myself, the promise of in-car delivery is a game changer. When I returned home to my car parked on a nearby street, the package was safely waiting for me.

There are some restrictions on what can be delivered to your trunk. Packages must not weigh more than 50 pounds, exceed 26 x 21 x 16 inches and can’t be valued at over $1,300 or fulfilled by a third-party seller.

For now, the service will be broadly useful in cities such as Dallas, Los Angeles, Atlanta and Chicago, and it’s coming to more areas soon.

That is, until self-driving cars make car ownership a thing of the past.