Most car makers are behind when it comes to securing the network of communications in auto systems. Simple reason, up until the last few years they haven't provided the access to the main bus. But with more and more remote connections allowed to the car via wireless, and some of those accessing vital functions, they've opened up the potential for someone with a will and a way to start seeing how much access they can control remotely. It costs extra in engineering and tech inside the car to help prevent it and if the car makers don't have to spend the extra in costs for the vehicle they simply won't.
The same kind of problem exists in industry. Most companies do not spend the resources necessary to properly secure their company networks and keep them secure with a trained staff, because it's not cheap to do so. So as we see they continue to be "hacked" and their networks penetrated and then we see the scramble to spend a buttload of money after the fact both in discovering what happened and trying to prevent future repeat compromises.
With that said, it's also Chrysler. Remember the 2013 Jeep Grand Cherokee and it not being able to pass the Moose Test ? Chrysler swore up and down there was nothing wrong with the vehicle and it was the testers incorrect methods that were causing the failures. Yet magically the 2014 version does now pass the test. (cough)