EMBED >More News Videos Amazon has announced a new delivery option: the trunk of your car.

EMBED >More News Videos The Amazon in-car service is available in 37 cities, including Chicago, and free for Prime Members.

CHICAGO (WLS) -- Amazon wants to deliver your next package to the trunk of your car.The in-car service is available in 37 cities, including Chicago, and free for Prime Members, the company announced on Tuesday.While the service may keep packages more secure, as Amazon said it has taken steps to ensure privacy."The benefit is primarily for the customer," said Alyssa Bronikowski, an Amazon spokeswoman. "We are always innovating on behalf of our customers and this is something we heard from them and we always want to provide convenient shipping options and we want to make sure they can receive their deliveries in the most convenient way."Customers would need to download the Amazon Key App and link their Amazon account with their connected car service account, then confirm and register a delivery location. Once the set-up is complete, customers can shop on Amazon.com and select the "in-car" delivery option at checkout.On delivery day, customers will get a delivery window and notification when the driver is headed to their car. Amazon locates the car with GPS and scans the package.Then, the vehicle is unlocked through the car's connected service like On-Star and then the driver places the package in the trunk.After that, the driver requests that the vehicle be re-locked. Once the delivery is completed, the customer gets a notification.Amazon plans to roll out the option to other cities over time, but it only works with certain vehicles so far -- Chevrolet, Buick, GMC, Cadillac and Volvo. The cars must be a 2015 model or newer and be OnStar-equipped (On Call for Volvo).One security analyst said the in-car delivery works because, in part, of their choice to work with OnStar."OnStar is already a proven technology and Amazon has formed a formal relationship with that technology provider for connected cars," says Brian Reed, chief mobility officer for Chicago-based cyber security firm NowSecure. "We have been trusting that in millions of GM cars for years, so we should be happy that Amazon is using a standard way versus trying to come up with some proprietary way to get into my car," he explains.Last fall, Amazon launched a new service which allowed customers to receive deliveries inside their home, and grant secure home access.However, as popular as two-hour delivery has proven, consumers have often drawn a line at allowing strangers into their homes.But Reed said the car is less risky for some consumers."I don't keep anything of value in my car," said Elizabeth Triscari, an attorney in regulatory affairs not affiliated with Amazon.Chicagoan Semaj Neville agrees. Amazon is "genius" with what they do, he says. "They keep reaching forward."Car delivery is Amazon's latest effort to streamline the online buying experience, as well as combat "porch pirates" -- people who steal packages from homes.The service will not work in garages and other gated environments where satellite signals are hard to get. But the company is saying if anything goes wrong during delivery, "we'll make it right."