• Amazon shut down its in-car delivery service, which enabled delivery people to securely drop off packages in Prime users' car trunks.
• The offering was an extension of Amazon Key, the company's array of services that enable delivery drivers to leave packages in garages, homes and businesses.

Amazon has shut down its service that delivered packages to the trunks of customer's cars.

The company notified Prime users on Thursday that the service, called Key In-Car Delivery, is being "suspended indefinitely," according to an email viewed by CNBC.

"While our plan was to reactivate In-Car Delivery as soon as we could, it will remain suspended indefinitely," the email states. "We apologize for any inconvenience and thank you for being a loyal Amazon customer."

An Amazon spokesperson confirmed the company is shuttering the in-car delivery service. The spokesperson added that Amazon paused in-car delivery last March and planned to resume it, but is now focusing on in-garage delivery and building out additional Key offerings.

Amazon launched its in-car delivery service for some Prime members with select vehicle models in 2018. The offering was an extension of Amazon Key, the company's array of services that enable delivery drivers to leave packages in garages, homes and businesses. In-car delivery was compatible with vehicles from carmakers like Ford and Volvo.

Amazon has pitched these services to Prime members as a way to keep their packages or groceries safe from weather, damage and theft. The services have also raised concerns around the prospect of giving a stranger access (albeit, limited entry) to your car, home or garage.

In the notice on Thursday, Amazon directed Prime users to try its in-garage delivery service and sweetened the offer with $30 off their first delivery, along with a free Chamberlain myQ smart garage controller, which enables Amazon to operate a user's garage door opener so that it can be opened by a delivery person.

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