"People's cars have already started turning their owners in. Scott E. Knight, a California man, was convicted last year for the killing of a Merced, Calif., resident in a March 2001 hit-and-run accident; police tracked him down because the OnStar system in his Chevy Tahoe alerted OnStar when the airbag was set off.
Transportation experts say that if these sensor systems can provide crucial information for emergency aid workers and for vehicle research, lives will be saved. The federal government is considering rules that would standardize the information that black boxes provide, along with ways to gather the information."
The article is full of more examples of tracking -- from a stalker putting a transceiver in his ex's car, to tire RFID tags, to that rental car company that fined a customer for speeding (the fine was illegal, but the tracking was not). One expert suggests something Vanessa mentioned -- in the future, we can pay more to 'opt out' of the tracking when buying or renting a car. Higher insurance or higher fees.
OnStar, like cell phones, pays for itself with subscription fees or upfront costs. The potential for spam is low. But the potential to report speeding, loud music, changing lanes without signaling, not properly defrosting the windows before you go to work... that's mighty annoying, too. Maybe they won't call the cops on you, maybe they'll call the insurance company and you'll get more points at the end of the year. That's more annoying than location-spam, methinks.