Cars, internet and hackers
Onstar is basically a microprocessor with custom software connected to the car's OBDII computer using satellite and cellphone technology. Each car has a phone number, EIN and IP address. It is no more sophisicated than a pc with the same configuration. Because Onstar uses the same computer system in all vehicles, it would, in theory, be easier to hack into an onstar equiped car than one with a PC.
As with any new technology, the media has to blow everything out of porporation. Can a car be hacked? Yes it can and probably will, however, it is no cause for alarm.
Just my 2 cents worth.