Get into my car ... Amazon begins delivery to vehicles in U.S.

Amazon's latest perk ... free delivery to your car.

The Seattle company on Tuesday began offering delivery in 37 U.S. cities to Amazon Prime members who own newer General Motors or Volvo vehicles.

The company will expand the number of locations as well as eligible vehicle makes and models going forward.

Amazon has steadily expanded its reach into places long considered no-go zones for most people outside of the immediate family, starting with smart speakers in the home that await voice commands to come to life.

The car delivery option is not available in Canada, but the company said it hopes to "one-day offer the service to Prime members around the world, including to those in Canada."

Last year, Amazon launched Amazon Key which lets those who with a Wi-Fi-connected lock to unlock their front doors so that packages could be left inside. Earlier this year, the company acquired Ring, which makes Wi-Fi-connected cameras and doorbells.

The in-car delivery service is available to members of Amazon Prime whose cars are parked in publicly accessible areas, such as on the street in front of an apartment building, at a workplace parking lot, or in a driveway. Amazon won't deliver to a private parking garage or other places where access to a vehicle is not readily available. Packages are placed in the vehicle's trunk or out of plain sight.

Deliveries are available right now to Prime members with 2015 year or newer Chevrolet, Buick, GMC or Cadillac vehicles with GM's OnStar connected-car service, and those with a 2015 or newer Volvo vehicle with an active Volvo On Call account.

Customers must download the Amazon Key app to which they can link a connected car.

On the day a package is scheduled for delivery, customers can use the Amazon Key app to confirm that their car is parked in a place where a delivery can be made.

The app also provides notifications with an expected four-hour delivery window and notifies customers when the package is on its way and when it's been delivered. Customers can track when their car was unlocked and relocked through the app, where they can also rate the experience.

"Receiving a package securely and reliably in your car, without you having to be there, is something we think many people will appreciate," said Atif Rafiq, chief digital officer at Volvo Cars. "This mix of car and commerce is starting the next wave of innovation and we intend to be at the forefront."

To check eligibility and to sign up for Amazon Key In-Car, visit amazon.com/keyincar.