Auto companies hope that the vehicle data will one day generate billions of dollars in e-commerce, though they are just beginning to form strategies for monetizing the information. Apple and Google already make money from smartphone owners by providing a variety of products and services, from digital music to targeted advertising, and connecting phones to car systems will almost certainly extend their reach.
But as infotainment systems such as Apple's CarPlay and Google's Android Auto become more widespread, auto companies hope to keep tech providers from gaining access to a wealth of potentially profitable information collected by computer systems in cars.
Some auto companies have specifically said they will not provide Apple and Google with data from the vehicle's functional systems - steering, brakes and throttle, for instance - as well as information about range, a measure of how far the car can travel before it runs out of gas.
"We need to control access to that data," said Don Butler, Ford Motor Co's executive director of connected vehicle and services. "We need to protect our ability to create value" from new digital services built on vehicle data.
The stakes are potentially huge: General Motors Co  told investors earlier this year that it expects to realize an additional $350 million in revenue over three years from the high-speed data connections it is building into its cars.

Auto companies hope to profit from in-vehicle data in a variety of ways, including the provision of travel plannings ervices and auto repair and service information they hope will bring drivers to dealerships. They also expect to work with insurance companies, providing information that would allow insurers to base their rates on a driver's behavior behind the wheel.
While many automakers have signed up to use CarPlay and Android Auto, systems designed to make it easier and safer for drivers to use the apps and features on their smartphones while driving, some car companies also have designed their own systems.
Several automakers said they are sharing minimal vehicle information that directly affects the performance of third-party infotainment systems - for example, GPS coordinates to enable navigation; information about whether the dashboard screen is in day or night mode; and notification of when vehicles are in reverse gear, so rear-view video displays can be activated.
The car companies recognize that Apple and Google can glean a wealth of information from the mobile devices that users bring into the car, said Thilo Koslowski, vice president and automotive practice leader at consultant Gartner.
As for Apple's and Google's interest in connecting with drivers, he added, "it's all about tying you into their ecosystems."
Vehicle owners who bring their mobile devices with them can elect whether or not to connect those devices inside the car.