The connected car will be an incredible convenience or an intrusive nightmare, depending on your tolerance. For automakers, it could be a gold mine.

As you might have suspected, your car is spying on you. Fire up a new model and it updates more than 100,000 data points, including rather personal details like the front-seat passenger’s weight. The navigation system tracks every mile and remembers your route to work. The vehicular brain is smart enough to help avoid traffic jams or score parking spaces, and soon will be able to log not only your itineraries but your internet shopping patterns.

The connected car will be a wonderful convenience or an intrusive nightmare, depending on your tolerance. For automakers, it could be a gold mine, which is why the industry is building firewalls to keep the likes of Google Inc. and Apple Inc. at bay and hoping to pry you away from their phones and apps when you’re motoring.

“Everyone is trying to control the screens in the car,” says Tony Posawatz, CEO of the consulting firm Invictus iCar and one of the developers of the Chevrolet Volt. “There is tremendous value in the data, and they are trying to figure out how to get it.”

The dashboard battle is gearing up as cockpit technology rapidly advances. Once self-driving cars are the norm, people will have the downtime to become truly mobile consumers. (Granted, that may seem further away after the recent death of a Tesla Model S owner who was using its Autopilot system.) Ford Motor Co. and others are already angling to give the Google’s of the world limited to no access to the juiciest data that will be amassed once millions of people are shopping in seat belts.