Amazon wants to get inside your car. Last year, the e-commerce giant launched a new service that allowed customers to have packages delivered to the trunks of their vehicles. To start out, only General Motors and Volvo vehicles were eligible. Today, that service has been expanded to include 2017 model year and newer Ford and Lincoln vehicles.

There are a few caveats: the service is limited to 50 US cities, and the vehicles must come equipped with a modem that allows them to connect to Ford’s connected car cloud services, FordPass Connect and Lincoln Connect. Only Amazon Prime subscribers are eligible. Packages that weigh over 50 pounds, are larger than 26 x 21 x 16 inches in size, require a signature, are valued over $1,300, or come from a third-party seller also are not eligible for in-car delivery.

“I think this is a great opportunity for Ford to offer its customers one more service and a little bit of a value on why [they] have a connected vehicle,” said Lorin Kennedy, who works on product marketing at Ford.

“one more service and a little bit of a value on why [they] have a connected vehicle”

Setting up the service requires signing up for both Amazon Key and FordPass or Lincoln Way, authorizing in-car deliveries, and then connecting the accounts. You’ll also need to add your Ford car to your Amazon Key app and include a description of the vehicle, so Amazon’s couriers will be able to locate it. The car will need to be parked within a certain radius of an address used for Amazon deliveries, so either home or work. Driveways, parking lots, parking garages, and street parking are all eligible locations, as long as it’s not at some random address across town.

After selecting in-car delivery, Amazon sends a series of notifications to let you know that the package is on its way. At any point, you can choose to change delivery locations or “block access” to the car in the Key app, if you need to run a quick errand or your car won’t be immediately accessible to the delivery person, for example. Amazon will then default to your backup delivery location if access to the vehicle is blocked. To find your car, Amazon’s couriers will have access to its GPS location and license plate number, as well as an image of the car.

Amazon is increasingly interested in the in-car experience as it seeks to grow its voice assistant and delivery services. The company has been able to convince some major automakers — Toyota, BMW, Ford, and, most recently, Audi — to allow direct Alexa integration with their infotainment systems. But not every automaker is going to acquiesce to Amazon’s integration demands. For drivers of those vehicles, Amazon offers an aftermarket device called the Echo Auto. The credit card-sized gadget sits on your dashboard and brings Alexa capabilities to your car via an auxiliary jack or over a smartphone’s existing Bluetooth setup. Amazon recently said it had received over a million preorders for the device.

Ford is also using the Amazon news to tout its other connected car services. The automaker recently began working with on-demand car wash services like Spiffy, Rub a Dub, and Sparkl.

Letting third parties track the location of your car will seem intrusive or unnecessary to some customers. Others may be concerned about privacy or theft risks. Kennedy said the onus is on the owner of the vehicle to determine how much access they want to give to these companies.

“We do ask customers to consent to giving Amazon permission to lock and unlock their vehicle so that they’re aware of exactly what information [they’re giving] and what Amazon is doing with that information,” she said.