The report said that, logically, "the least hackable cars contain the fewest computerized and networked components. That way, the vehicle's networks can't communicate with other physical components of the vehicle," including functions like steering and braking.
Connectivity in Audi's flagship A8 sedan includes a Wi-Fi hotspot and a highly sophisticated infotainment and navigation system. In addition, the engine, gearbox, steering, suspension and brakes are networked together and work in combination with such active controls as lane-keeping assist, adaptive cruise control, front crash avoidance and parking assist.
The electric-powered Tesla Model S packs many of those features as well, but it also takes connectivity to new levels with high-speed Internet capability that facilitates over-the-air software updates, which might seem to make the car even more vulnerable to hacking.
But on vehicles like the A8 and the Model S, critical systems like engine, brakes and steering, even though they may be networked, are well separated from the wirelessly connected computers, which makes them less susceptible to remote hacking.
In fact, as previously reported by Edmunds, although a Tesla Model S was hacked recently, the hackers needed physical access to the vehicle in order to gain control and shut it down at low speed. They were unable to hack the Model S wirelessly, and almost immediately after the incident Tesla Motors issued an update intended to prevent even physical hacking.
The other end of the PT&C|LWG list — the "most hackable" group — is led by the 2014 Jeep Cherokee, which was proven vulnerable this past July when Wired.com reported that researchers were able to take control of the SUV, disabling its engine and manipulating the air-conditioning, door locks and radio.
As noted by Edmunds, Fiat Chrysler Automobiles subsequently issued a recall of 1.4 million U.S. vehicles, including Jeep Cherokee models that were equipped with certain infotainment systems with 8.4-inch touchscreens.
Contacted for comment on this study, an Infiniti spokesperson told Edmunds: "Infiniti engineers and security teams are reviewing the findings of this study. Our current understanding is that there is no indication any Infiniti vehicle was actually exploited by the authors in the study. As the potential for 'hacking' into the electronic systems of all vehicles may grow, we continue to integrate security features into Infiniti vehicles to help protect against cyber-attacks."
And a Ford spokesperson commented: "There is minimal detail so it's difficult for us to comment on it without being able to understand the process and criteria behind the study."
Representatives from Fiat Chrysler said they had no comment, and those from Cadillac did not respond in time for publication.
Edmunds says: Although not exhaustive, this list provides some guidelines for consumers who are concerned about vehicle hacking.