Imagine driving down the road on a long trip, and it's been awhile since you ate and gassed up. You pass a large billboard showing, "Hi, Dave. 3 hours since last stop. Taco Bell next exit." GM has patented this technology that will couple the Onstar system to an advertising grid. The patent was filed almost two years ago.

U.S. Patent via Google
http://www.google.com/patents?id=VzsFAgAAEBAJ

Application number: 12/872,664
Publication number: US 2012/0054028 A1
Filing date: Aug 31, 2010

Two weeks ago, a patent filing by General Motors was uncovered that proposed using data collected from its OnStar service to tailor public advertisements to individual drivers.

Like the billboards Tom Cruise encountered in Minority Report, the OnStar-linked ads would be
tailored to passing motorists based on personal information they’d shared with their telematics service. Perusing the patent’s text, nightmare scenarios flooded our thoughts. Kids in the backseat? Be prepared to see ads for Happy Meals and nearby amusement parks. Headed
to the doctor’s office? A friendly reminder to schedule a colonoscopy, in flashing 40-foot letters.

The most alarming aspect of the patent is how it proposes gathering personal data. Expectedly, the patent covers the use of location-based information from OnStar’s turn-by-turn navigation system. But more intrusively, it also includes the use of in-vehicle cameras to determine unspecified demographics of vehicle occupants. Even power seat positions could be used to estimate
the age of a driver.

Rest of Article
http://www.wired.com/autopia/2012/05/onstar-billboards/