carjacking vehicles with constant internet connections and GPS's doesn't strike me as an extremely profitable maneuver.
the whole "car detects obstacle in an untrafficed area, stops, door is opened, passenger gets out, passenger gets back in, changes destination to a place not proximate to anywhere they've ever been before" process also sounds like the sort of thing that would justifiably raise a bit of a red flag. maybe not an automated call to 911, but it should probably dump all records to the cloud and trigger a call from an onstar operator or similar.
I think the idea is that they'd stop the car, incapacitate the driver, grab what they can and run like hell.
Besides, if we're talking about this happening in the "bad" parts of town, the car can call 911 and broadcast is position all it likes. There won't be any immediate response.
Finally, people who do this long enough will eventually figure out what to disconnect to allow themselves enough time to do what they want with the car- like today's car thieves do with modern car alarms.
They straight up throw a car in a cube van and drive it off to the chop shop. Not a huge leap to faraday-cage the transport vehicle.. probably acts as one already, come to think of it.
