The service is expected to be launched later this year.
AT&T is working with eight automobile manufacturers to provide exclusive mobile content for connected cars.
The telecommunications firm is planning to offer free or paid games and videos exclusively in selected cars, in order to sell more data.
General Motors, Audi, Ford Motor and several other companies are working to bring the service later this year.
AT&T senior vice president of emerging devices Chris Penrose was quoted by Reuters as saying, "It’s no different than being able to hook onto a Wi-Fi hotspot anywhere and get access to content you already subscribe to and get unique content that you could only get in the back of the vehicle."
Penrose said AT&T are in negotiations with its auto industry partners and content firms to bring new data such as special shows or games on phones and tablets to connected cars.
General Motors has started testing new content on its OnStar in-vehicle service to live operators for directions or emergency help.
Penrose said AT&T is exploring business models including revenue share for data, content and advertising with automakers, content and retail partners.
A landing page or a portal will be designed for users to log in to access content. They can get vehicle service updates and purchase data.