Look under the dash of a 2009 or newer Corolla. There is a computer controlled electric motor about 9" in diameter. It is the power steering. All the newer hybrids and most high end cars have electric steering racks.
Anything on the CAN bus is hackable. I have seen 54 onboard computers on the CAN bus (Lexus LS 460). Imagine the power seat moving foreword and up while the tilt and telescope steering column moves back and down for example.
Yep, my wife's RX-350 has the electric steering setup you describe. And all the articulated bits and pieces on the inside that require sensors and computers to operate. I'm not a technophobe, but having a computer network between me and the powertrain or steering just creeps me out.
BTW, I'm a Niven fan. Great screen name.