Since the service was introduced back in 2017, Cadillac CT6 owners have been enjoying a complimentary three-year trial of Cadillac's advanced Super Cruise semi-autonomous driving service. This free trial will expire very soon for some owners, however, and now CNET has learned how much it will cost if they want to continue using it.

According to the publication, Cadillac's Super Cruise will require a subscription of $25 per month. Early adopters of the 2018 Cadillac CT6, on the other hand, will get an extra one-year free trial after the initial trial period expires.

When the service expires for owners of the 2018 model year CT6, US customers will be able to purchase a standalone Super Cruise plan for $25 a month, which adds up to $300 a year. If you're already subscribed to other select OnStar and GM Connected Services bundles, Super Cruise can be added for an extra $15 a month.

Owners that don't subscribe to Super Cruise will still be able to use the car's lane-keep assist, and adaptive cruise control, but Super Cruise functions will no longer work meaning you'll no longer be able to enjoy hands-free driving on over 200,000 miles of US highways.

A Cadilac spokesperson also added that a subscription will activate map updates and the "precise GPS corrections required for Super Cruise to function." The car will also be able to contact OnStar if the driver fails to respond to alerts asking them to take over control.

Initially, Cadillac's Super Cruise was only available for the now-discontinued CT6, but was recently added to the CT4, CT5, and the new Escalade for the 2021 model year. By 2023, General Motors plans to make Super Cruise available for on 22 new vehicles, so the service won't be exclusively available for Cadillac models for much longer.