SALT LAKE CITY -- In its continued trek towards retail omni-presence, Amazon will now deliver packages to the trunk of your car, or to the cabin for that matter.

Including Salt Lake City, Amazon launched it's "Amazon Key In Car" program, allowing members of it's prime program to ask for packages to be delivered to their car, so long as it's parked in a public place.

There are limits. A customer has to own a 2015 or newer GM or Volvo vehicle with an active On-Star or Volvo On Call account. Amazon says they plan to partner with other car companies in the future.

Here's how it works: The Amazon Key app gives customers the ability to allow Amazon couriers to unlock their cars during a specific window of time. The courier would use their app to unlock the car, place a package inside, and lock it after the delivery. Each step is communicated to the customer through the app.

Amazon insists the technology is secure and they will cover costs if something goes wrong.

"In the off chance should something happen, whether it's during the delivery or after the delivery, the service is backed by the Amazon happiness guarantee so we would always make it right for the customer," Amazon Spokesperson Alyssa Bronikowski said.